Anti-Kell Antibodies

* If you are dealing with anti-Kell antibodies and are searching for information, don’t be scared or discouraged by my story. Your baby will probably be fine as long as you educate yourself and make sure you and your baby get the correct treatment. Make sure to check the bottom of the page for the steps you need to take to ensure you are getting the best treatment possible. For more resources check out The Allo Hope Foundation.

Before developing anti-Kell antibodies, I had two normal pregnancies and delivered two healthy baby boys, both born at 41 weeks. When I was pregnant with my third baby, I discovered at nine weeks that I had anti-Kell antibodies. I had never heard of anti-Kell antibodies and couldn’t find much information online. It was terrifying. Long story short, I have had four Kell sensitized pregnancies with VERY different outcomes. Lucy was stillborn halfway through the pregnancy. My next baby, Nora, was born healthy at 37 weeks 6 days and has no lasting effects from the antibodies that tried to kill her in the womb. After Nora we had Callum, who was born at 34 weeks 4 days and is now a healthy, super smart preschooler. Our last baby, August, was born at 37 weeks 1 day and is a healthy one year old now. Over the past nine years I have done a lot of research and asked a lot of questions, and I now have a much better understanding of this disorder than when I was first diagnosed. I will do my best to explain anti-Kell antibodies and how they work. The more you understand, the better you can advocate for your baby and keep your baby safe.

Disclaimer: I am not a doctor or a medical professional. This is what I understand about anti-Kell antibodies.

Kell is an antigen found in some people’s blood, so basically it’s kind of like a blood type. It’s not dangerous at all. My husband, Josh, and my children, Asher, Lucy, Nora, Callum, August and possibly Liam all are positive for the Kell antigen. About 9% of Caucasians are Kell antigen positive. I don’t have the Kell antigen, and that’s where the trouble begins. My pregnancies with Liam and Asher were totally normal and healthy because I did not have anti-Kell antibodies yet. When I gave birth to Asher (who has Kell antigen positive blood) some of his blood leaked out and mixed with my blood. This is normal during childbirth, especially a vaginal delivery of a 10 lb baby! Because my blood is Kell negative, my body saw Asher’s blood as something foreign and dangerous. My body thought Asher’s blood was a virus, even though it wasn’t. When our bodies get a virus we make antibodies. Antibodies are like the soldiers who go and kill the virus. When we get vaccinated we are injected with a little bit of the disease, then our bodies produce antibodies to kill it. After the vaccination, our bodies are well armed with antibodies to kill the disease and that’s what keeps us safe. So, because my body thought Asher’s Kell positive blood was a virus, I produced anti-Kell antibodies to destroy it. The antibodies I produced were specifically designed to find and destroy red blood cells containing the Kell antigen. This is called being sensitized. It didn’t hurt Asher because it happened right as he was being born. He got out just in time. There is another way that women can become sensitized. If a Kell negative woman is given a blood transfusion with Kell positive blood, her body could react the same way mine did when I gave birth to Asher- by creating antibodies as a response to being exposed to Kell positive blood. There are also recent studies that show that intravenous drug abuse can possibly cause sensitization as well.

My husband found out through a simple blood test (done by my regular OB) that he is heterozygous for Kell, which means he has the recessive gene. This just means that each one of our kids had a 50% chance of being Kell positive like Josh or Kell negative like me. The only way the antibodies can hurt the baby is if the baby is Kell antigen positive. If the baby is Kell negative, the antibodies cannot affect him/her and it will be a “normal” pregnancy. With each pregnancy we were hopeful that our baby would have my blood type, but we always got the wrong 50% because our last five kids have all been Kell antigen positive. If Josh had been homozygous for Kell, our kids would have all had a 100% chance of being Kell positive. Most people who are positive for the Kell antigen are heterozygous like my husband.

My body will always produce anti-Kell antibodies, I can never get rid of them. I have basically been vaccinated against my husband’s blood type, so anything inside my body with his blood type will be attacked by my antibodies. Unfortunately, like I mentioned earlier, Lucy got her Daddy’s blood type. She was Kell positive. She was a healthy, kicking girl throughout the first trimester and the beginning of the second. Babies don’t produce their own red blood cells until the end of the first trimester/beginning of the second. When Lucy started making her own blood, my anti-Kell antibodies crossed the placenta and recognized her blood as something dangerous. The antibodies started attacking and destroying her red blood cells. This can make the babies become anemic and eventually can cause fetal hydrops or even death if the fetal anemia is untreated. Thankfully, with the correct monitoring, fetal anemia can be caught in time to treat before it becomes severe.

The way the anti-Kell antibodies are measured is something called a titer (pronounced “tight-er”.) The titer shows the amount of antibodies in the mother’s blood. When a mother’s titer reaches 4 it becomes critical for the baby. This just means that the antibodies can affect the baby at that level. My titer was 1,024 from the very beginning of my pregnancy with Lucy. Titers can be expressed as a ratio like this 1:16 or just the number itself, 16. A titer of 1:16 and a titer of 16 mean the same thing. The critical titer for Kell is 4 and the critical titer for all of the other antibodies is 16. I have heard different “facts” about antibody titers from different people. Some believe that the titer rises as the antibodies attack the baby, so a rising titer indicates a Kell positive baby, and a low titer indicates a Kell negative baby. Some believe that every subsequent pregnancy will be more dangerous because the titer will be higher. The one thing about titers that everyone agrees on is that they are unpredictable and are not to be trusted. My titer never changed throughout my pregnancy with Lucy, during the two years when I wasn’t pregnant and during my pregnancy with Nora, who was Kell positive also. It has always been 1,024. It did go down to 512 with my last baby, Callum, and was 256 at the end of the pregnancy. Before I got pregnant with August we tested my titer and it was 2,048, the highest it had ever been. In general, the higher the titer, the more dangerous it is to the baby, for example, we can assume that a woman with a 1,024 titer will have a much higher chance of having an affected baby than a woman with a titer of 2. However, the extent to which the baby is affected relies on several different factors besides the titer- how aggressive the antibodies are, how the baby handles the antibodies, whether there are other antibodies present, the baby’s gender (girls tend to do better than boys, supposedly) and especially, the monitoring and treatment given during the pregnancy. Just because your titer is very high, it doesn’t mean you are going to lose your baby, and it doesn’t mean your baby is Kell positive. Just because your titer is low, it doesn’t mean your baby is safe and it doesn’t mean your baby is Kell negative. The best thing you can do for your baby is find a good MFM (maternal fetal medicine specialist) who is knowledgeable about these antibodies (or who is willing to learn), educate yourself on the disease and make sure you are getting the right treatment and monitoring during the pregnancy. I had the same titer with my daughter Lucy and with my daughter Nora. With Lucy I did not receive the right monitoring and treatment, so she was stillborn. With Nora I did receive the right monitoring and treatment from very experienced MFMs and she is now a healthy little girl. My sons, Callum and August, also received the correct monitoring and treatment and they are perfectly healthy now.

So what does the monitoring and treatment look like? Babies should be monitored very closely and can be given an intrauterine blood transfusion if they become anemic. Regular ultrasounds or even in depth level 2 ultrasounds cannot detect fetal anemia, unless the anemia is so severe that it has started compromising baby’s organs or fetal hydrops has started. The goal is to discover and treat the anemia before it ever gets to that point. Doctors can detect and measure fetal anemia by doing an MCA doppler scan. MCA stands for middle cerebral artery. It’s the central artery in the baby’s brain. A really powerful ultrasound is used to measure the blood flow through this artery. If the blood is moving too fast, they know the baby is anemic. They give the baby an MoM (multiples of median) score that shows how anemic the baby is. The median MoM is 1. If the baby’s MoM starts creeping up and gets to a 1.5 that means he/she is anemic. Once the MoM is 1.5 or over, the doctor should do an intrauterine blood transfusion (IUT) on the baby to resolve the anemia. Usually babies aren’t affected until late in the second trimester or early in third trimester, but in extreme cases they can be affected as early as 15 weeks. The baby can’t be harmed by the antibodies in the first trimester. The earliest loss I have seen from these antibodies was at 14/15 weeks, although some women say they have lost babies as early as 13 weeks. Lucy had her first MCA scan a day or two before 18 weeks and her MoM was 2.5. She was severely anemic. They did an IUT on her the next morning. My baby Nora had her first MCA scan at 15 weeks and weekly after that. She had 5 IUTs. My son Callum had his first MCA scan at 14 weeks and had 3 IUTs. Baby August had his first MCA scan at 14 weeks and needed 7 IUTs. If you have a critical titer, you should start MCA scans by 16-18 weeks and have them done weekly to check the baby for anemia. If you have a titer in the hundreds or thousands it is best to start MCA scans by 16 weeks.

When an IUT is performed, the doctor basically sticks a really long needle through the Mom’s belly into the uterus and into the baby’s umbilical vein. They put fresh, Kell negative blood packed with red blood cells into the baby. If the baby is too small and the doctor can’t get into the vein they just stick the needle into the baby’s abdomen and put the blood there (called an IPT.) The blood placed in the baby’s cord relieves the anemia immediately. The blood placed in the baby’s abdomen is absorbed over the following days/weeks and can act as a reserve, slowly filling baby up as she becomes anemic over time. Some doctors prefer to put blood into the baby’s cord and belly to resolve the anemia immediately and give baby a future reserve of blood in order to get more time between IUTs. Some doctors prefer to only put blood into the cord and will need to perform the next IUT sooner. If you want to know more about the IUT procedure you can read about my transfusions with Nora here. Dr. Moise always rescanned Nora the day after an IUT to make sure she handled the procedure ok. Dr. Trevett also scanned my babies 24 hours after every IUT. Usually, if there is a complication from the IUT it happens within the first 24 hours after the procedure. My little Lucy was left for seven days after her IUT before they would scan her to see how she handled the procedure. Make sure you only let experienced MFMs perform your IUT.

Some women have extremely aggressive antibodies, so the concern is that the baby will become anemic before she is big enough to have an IUT. Only very skilled and experienced MFMs can perform a successful IUT on a baby younger than 20 weeks. The smaller the baby, the more difficult and dangerous the procedure is. One way to protect the baby until she is big enough for an IUT is to give the woman plasmapheresis and IVIG treatments or IVIG alone. With Nora, Callum and August I started plasmapheresis and IVIG around 10 weeks and the treatments saved their lives. These treatments are usually only given to women who have had a previous loss or a severely affected baby in a previous pregnancy, or women with extremely high titers.

One last thing- a lot of people ask me why I couldn’t get “the shot” to prevent my body from making the antibodies in the first place. There are many different types of red cell antibodies, and the most common type is anti-D antibodies (Rh disease.) Because it’s so common they developed a preventative shot called RhoGAM that can be given to a pregnant woman before she develops antibodies and it keeps her baby safe (although it does fail at times and some women still end up developing anti-D antibodies.) There is no preventative shot for Kell. After Lucy died I asked my doctor why they haven’t developed a preventative shot for Kell like rhoGHAM. He said it doesn’t affect enough people and isn’t profitable for the pharmaceutical companies.

UPDATE- Dr. Moise is currently working on a new treatment for women with anti-Kell antibodies (and other antibodies.) There might ACTUALLY be a shot one day that can protect these babies from anti-Kell antibodies. You can learn more about this possible new treatment HERE.

* For women with anti-Kell antibodies: Please don’t be scared by my story. What happened to Lucy is VERY rare, almost unheard of. Your baby will probably be fine as long as you make sure you are getting the right treatment. I’ve heard that most babies in a Kell sensitized pregnancy have a great survival rate. If you just found out you have anti-Kell antibodies you need to do several things:

  • Find out what your titer is
  • Have the baby’s father tested for the Kell antigen (NOT anti-Kell antibodies)
  • If the baby’s father is Kell antigen negative, the baby cannot be harmed by the antibodies and is safe.
  • If he is positive for the Kell antigen, have him phenotyped to find out if he is homozygous or heterozygous for Kell to know if your baby has a 100% chance (homozygous) or a 50% chance (heterozygous) of being Kell positive.
  • Get a referral to an MFM
  • If you have a titer of 1:4 or higher, make sure you have your first MCA scan between 16-18 weeks and weekly after that. If your doctor wants to wait until after 18 weeks for the first MCA scan, you should insist on it and if they won’t budge, ask to be referred to a hospital that will. With Nora, I had my first MCA scan at 15 weeks.
  • Buy a notebook or journal and keep it with you at every appointment and every procedure. Write down all the information your doctor gives you. Think of all the questions you want to ask before each appointment and have them written down in the notebook. Write down all the answers. (I also had encouraging Bible verses written down that helped a lot.)
  • Remember that YOU are the only person who can speak for your baby. You are your baby’s voice. If you are unsure about something, don’t be afraid to ask the doctor. If you feel like something might not be right, go in immediately and have your baby checked out. Don’t be scared to look stupid or be annoying. That doesn’t matter when you compare it to the worth of your baby’s life. Read this post to avoid making this very common and dangerous mistake many women make.
  • If you have lost a baby to antibodies before, have had a severely affected baby before or have an anti-Kell or anti-D titer in the hundreds or thousands, read THIS
  • Feel free to email me or private message me on Facebook if you have any questions about anti-Kell antibodies: or just ask your question in the comment section below.
  • Remember that ultimately your baby’s life is in God’s hands. Try to rest in the fact that He loves your baby more than you do.

306 thoughts on “Anti-Kell Antibodies

  1. This is my third pregnancy with Kell antibodies.

    My girls are fine, both have my same blood, so they never were in any real danger – thank God.

    I intend on having an amniocentesis to find out this little one’s Kell type, hopefully it will again be like mine.

    I’m almost 14 weeks pregnant, and hope the amnio will enable me to have a less stressful pregnancy than the other two…

    • Hey Maria, that is awesome that your last two babies were kell negative. I’m assuming the father is kell positive? Do you know what your titer is? If you want to check the baby’s blood type you can also have your blood tested (has to be sent off to Europe) to find out whether baby is kell positive or kell negative if you want a less invasive choice. You can do it at 14 weeks and I can give you all the info you need to have it done. I keep meaning to post the info on my blog but haven’t gotten around to it yet (horrible, I know!) Or you can just do the amnio. We had the amnio done with our baby Nora and it was fine. Had the results back at around 17 weeks

      • I can’t remember exactly which one of us is positive (the initial testing was done 5 years ago, and I just got the Coombs test results yesterday, so I have to get my facts straight again now), but the children have a 50% chance of having the “wrong” blood.

        Titer is 1:128 (I’ve had higher with previous pregnancies).

        No I did not know you could find out in a less invasive way, and I live in Italy so perhaps I can find this test here.

        Do you have a link?

        Thank you for your help!

      • You are positive for anti-kell antibodies and your husband is positive for the kell antigen. That is a pretty high titer so make sure you start weekly MCA scans at 16 or 17 weeks unless you find out before then that the baby is kell negative. I just published a blog post with all the forms and instructions so that you can send your blood to the Netherlands to find out whether baby is kell positive or negative. If you come find me on facebook (Bethany Weathersby) I can add you to the Iso Moms group with women who are going through the same thing. The women are so supportive and helpful.

    • Your blog has been so helpful to us. A few weeks ago we found out I have kell antibodies and today we found out my husband has the homozygous Kell1 antigen gene, so baby is 100% Kell. My titer levels are at 32 so my MFM said to do the MCA scan at 20 weeks. I asked him twice if we could do it earlier and he said with my titer levels it’s rare to have the baby affected before 20 weeks and there is no intervention before then anyway. I want to trust him so that I can come to peace with this plan but I wonder if I should be pushing for an earlier scan or even requesting a phone consult with another MFM. I have been having such a hard time with this and I am in awe of your courage and strength. I pray every day that God will give me and my baby strength to get through this.

      • Hey Laurie, I’m so sorry your husband is homozygous. That is super disappointing, I know. Thankfully it doesn’t mean you can’t have a healthy baby though. And now that you know he’s homozygous you know baby’s antigen status without needing to do any tests so I guess that is a tiny silver lining? My husband is heterozygous but our last four (maybe all five) kids have been Kell positive and we had to do amnio/blood tests sent to the Netherlands to find out so it’s good you can skip that part. About your question, you are absolutely right that they should start scans before 20 weeks to check baby for anemia. With Kell even at a titer of 4 the baby can be affected and become anemic which is why weekly mca scans starting by 18 weeks are recommended. Your dr is also misinformed about interventions before 20 weeks. IUTs can be done as early as 15 weeks if baby is anemic that early and they can also start IVIG infusions to prevent/delay fetal anemia before 20 weeks. Another reason to start weekly scans earlier than 20 weeks is because serial MCA scans (several done over time) can give a more accurate picture of how baby is being affected by the antibodies. If they do scans every week and notice an upward trend then the doctors and family can prepare themselves for the likelihood of a transfusion and will know that the MoM (once it’s over 1.5) is probably accurate. That makes it easier to know when to transfuse. The more numbers you have, the easier it is to spot a trend. Keep pushing to start weekly MCA scans between 16-18 weeks and if they won’t then you should find a new MFM.

      • Thanks so much Bethany for your reply. It’s so nice to have knowledgeable support. I am going to contact my MFM and push for an earlier mca scan, thank you for the encouragement and information to do so! You and your blog have been a real blessing to us during this scary time.

  2. This has been a really good read for me and I will be passing this page on to all our family members that do not understand the anti-k situation as I think it is explained well and will help them a lot.
    We lost our beautiful son Hudson at 28 weeks on 29th Dec 2016 due to anti-k antibodies, we knew I had the antibodies from 10 weeks and placed on high risk pregnancy. I had blood tests done every 4 weeks to keep a track on the antibody levels, we had the blood tests done to work out my other half’s blood type and he is heterozygous so from a few blood tests my consultant ‘assumed’ that’s Hudson was the same as me and discharged me, 5 weeks after being discharged with no scans, blood tests for Hudson or anything having been done to keep an eye on us we had been informed that’s Hudson had died and that I would have to deliver him stillborn.
    We are trying to help research by allowing them to keep the tissue samples for research purposes as we feel that not enough has been done to raise awareness for anti-k.

    • Megan, I am so sorry that you lost your sweet baby Hudson. I was devastated to read your story. Losing a child is the worst pain imaginable. NO baby should ever die a preventable death. I am so sorry that this happened to you. I hope your doctor will be held accountable for what happened. They should have been doing weekly MCA scans to check Hudson for anemia. Come and find me on facebook so that I can add you to the Iso Moms group. Many women in the group have lost babies to these antibodies, and sadly, many of the losses could have been prevented. It is comforting to be in a group with other women who know how it feels (and it is helpful if you ever want to try again for another baby.)

      • Hi Bethany. Thank you for replying, I’m sorry it’s taken so long to reply but I didn’t see your reply. I will find you on Facebook as this is such a rare read so to speak to other mums who have had similar situations, I felt so isolated.
        We are planning on having a meeting and discussing everything with the consultant, to know if things were done properly things could have been different and to think I could have come home with my Hudson is heartbreaking.

      • When is your meeting? I would love to give you a list of questions to ask, if you’re open to it of course. I think I just saw your request on facebook so I’ll add you and talk more there!

      • Thank you so much for sharing your story! I have two wonderful healthy kids and have just found out I’m pregnant with baby number 3, and that I have anti-K antibodies. I had never heard of it before today, and while there is some information online it is quite technical and refers more to people who have had a blood transfusion. Having never had a transfusion, I assume we are the same as you and your husband – I must be negative and my husband must be positive, and one/both of my kids must be positive. Funnily enough, I have a negative blood type, which means that normally I would have needed the anti-D shots during pregnancy. Luckily, my husband also has a negative blood group (in fact we have the same blood type) so I have always been very smug about the fact that I don’t need the anti-D shots!!! Now it seems we have the anti-K problem. My titre is 4, so hopefully we won’t encounter any problems but I will be following your advice very closely. Thank you again for sharing, it made me feel less alone and more informed. I’m also very sorry for the loss of your Lucy. Wishing you all the best x

  3. Dear Bethany, Thank you so much for this post!
    My husband and I are in the process of starting our fight to stay pregnant (we won’t do IVF right away, we’ll start with insemination first to see will it work) and my blood test came back yesterday saying I am kell antigene negative (phenotype kell) .
    After reading your post I understand what that means and what are the dangers of it and I will absolutely have my husband tested to see if he is positive or negative like me. I wil be hoping he is negative, but I know that the chances are slim…
    To be honest, I am very scared and just the thought that my body would see my baby as a virus is quite unbearable, but I will monitor everything closely and hope for the best. Your text will serve me a lot! I live in France so procedures are different but there is transfusion during the pregnancy and from what I see on forums, most babies get born well and healthy, as you said, it just has to be determined on time!
    Thank you very much again! I will join the group on facebook.


    • Hi Maya, I hope your journey to your baby is smooth and boring! So, 91% of the population is kell antigen negative, like you. This means there is a 91% chance your husband is kell negative too! Even if he does happen to be kell positive (very unlikely) then your baby will still be safe since you don’t have anti-kell antibodies. It is actually very rare to develop these antibodies, even if your husband is kell positive and you are kell negative. I really don’t think kell will be a problem for you at all. Good luck!

  4. Hello!
    Your post had been the most informative and understandable article that I read so far about Kell-antibodies. 3 years ago when I got pregnant I was diagnosed with Kell-antibodies and was under constant supervision doing MCA scans every week until my daughter was born. My titer was low but I was bit scared anyway. Now my daughter is almost 3 years old.
    I’m pregnant again and when I was tested at 11 weeks the test was negative for Kell antibodies. I suppose they don’t disappear over time from the blood so why was the test negative for K? I got tested again last week at 19 weeks and it was positive for antibodies but didn’t detail exactly which ones. I suppose it’s the Kell again. I’m going back again tomorrow for another detailed blood test. Have you heard of Kell-antibodies disappearing and reappearing again? I’m so confused. I don’t live in the US and here in Europe and Asia they almost never heard of it and rarely test for such things 😦

    • Hi Sonya, so it isn’t that uncommon for an antibody to not show up in an antibody screen. Often, titers fluctuate, so if your titer was pretty low to begin with and then it went down, it can be too low to titer in an antibody screen. The antibodies are still there, they are just very weak and didn’t show up on the blood test. you will always have anti-kell antibodies, but that is awesome that they are so low. The general rule is that if your titer ever reached the critical level, EVER, in the current pregnancy or previous pregnancies, then you should be monitored as if your titers were critical, which means you should be having weekly MCA scans just to be safe. You should come join the Iso Moms group on facebook, there are a good number of women in the group who had the same thing happen to them. Send me a friend request (Bethany Weathersby) and I will add you!

  5. hi, i am 14 weeks pregnant and my doctor recently informed me that i am positive for little c antibodies. do you know how i can get my baby tested to see if she is + or – for little c? my understanding is that if she is negative like me, then we won’t have any major issues; is that correct?

    thanks so much,


    • Hey Lizzy,
      You are right, the baby can only be affected by your antibodies if she is positive. If she is negative like you, then it is a normal pregnancy and baby is completely safe from the antibodies. If you look at my blog post “Anti-Kell Antibodies: Is My Baby Kell Negative or Kell Positive?” you can get all the information about a maternal blood test you can have done to test your blood to find out whether baby is negative or positive for little c. Check out the links at the bottom of the page. The last one has instructions for little c. Print off the documents and bring them in to your doctor because he probably won’t know much about this blood test, but can definitely do it with the information i provided. It’s always helpful to have the actual documents in hand when discussing something “new” with your doctor. Oh, and you should send me a friend request on facebook (Bethany Weathersby) so I can add you to the Iso Moms group. There are a lot of women in the group with little c antibodies.

      • Hi Bethany,

        There are a few people on fb with your name. Which one is you? I am “Elizabeth Louise” and have a black and white photo of my three children as my profile picture.

        I will check out that information. THANK YOU SO MUCH!


  6. Hi Bethany. I’m currently pregnant with my third child (fifth pregnancy). When I was pregnant with my first, I tested positive for Kell antibodies, likely from a previous blood transfusion. My husband tested negative, so it was my understanding that this was no longer a problem. My current OB is saying that it can still be an issue. If he’s negative, how can the antibodies affect baby?

    He’s sending me to an MFM, so I’ll ask lots of questions there, I’m just trying to better understand the possibilities in advance. I just friend requested you on Facebook. Thanks for sharing your story and information.

    • Hey Amanda, so it sounds like you know more than your OB does about anti-kell antibodies. He is wrong. If your husband tested negative for the kell antigen, then your baby is 100% safe from your antibodies. If the father is kell negative, then the baby will be kell negative (both you and your husband are kell negative so there is no possible way for your baby to inherit kell.) If the baby does not have the kell antigen in his blood, then there is nothing for your anti-kell antibodies to attack. You an ask your OB to show you the studies that he is getting his information from. Ask him, “If my baby is negative for the kell antigen, what will my anti-kell antibodies be attacking? If the baby has no kell antigens for my antibodies to attack, how can the antibodies harm the baby?” I just saw your friend request so I will add you to the Iso Moms group!

      • Thanks so much for that information. This all makes so much more sense. I think I’ll ask that he be retested, because it’s been 6 years and neither of us remember 100%, but I’m almost positive my previous OB said “he’s negative, so nothing to worry about”.

  7. Hi, thank you so much for this blog. You have so much great information here and you are so brave for sharing your story. I would have loved to find a blog like this 7 years ago when I first found out that I had anti-Kell (and I was 7 weeks pregnant with my 2nd child). My daughter (who is Kell +) and I had a massive fetomaternal hemorrhage right before her birth, and she was born very anemic (unrelated to Kell) at 34 weeks and had multiple health issues at birth and on. My son ended up being Kell negative but I was monitored with MCA scans because we didn’t know his status. He was born healthy but both kids have special needs and ongoing medical issues. Fast forward 7 years and I am now 12 weeks pregnant with my 3rd child. I just got referred to MFM. My husband is heterozygous for Kell antigen. Is there still an active Facebook group that I can join? Starting to get anxious as I head into my 2nd trimester. Glad to see there is more information out there now. Thank you ❤❤

      • I am little k cellano o positive would I have trouble getting blood if needed
        not having any children had 4(hey are all fine did not get the little k ) can you help me

      • Hmmm, that is a good question. I don’t think they would have to match you with little k cellano blood, but if you were given blood that contained antibodies that could be a problem. But don’t they screen donated blood for antibodies before giving it to someone? My baby Nora is kell positive but for all seven of her blood transfusions she was given kell negative blood that contained no antibodies and she did great.

  8. Hi,
    I’m so glad you have shared your story and I am sorry for what you have been through.. I found out after 2.5 yrs trying to conceive and failing that one of my issues is that I have anti Kell 1:1 so very low. This may have been due to the 6 blood transfusions after the emergency c-section of my beautiful son number 2. My husband had bloods done today to test for Kell so we find out in two days. I understand my chance for baby to be harmed is low with 1:1 but my other concern turns to needing blood transfusions myself as I read that they do not generally screen for Kell as it is too expensive. This is not my only issue with conceiving so my dilemma is do I give up on the dream of one more or accept the risks involved. I’m scared especially seeing as I nearly died giving birth to baby #2. I have been going through a range of emotions lately it’s anger that the doctors knew about kell positive and negative why not test on pregnancy with both partners find out early and don’t give young women the incorrect blood I would have paid extra to have the correct blood. Ok rant had thanks for reading, I have lots to think about.

    • I’m so sorry for all the stress and frustration. Many countries in Europe screen donated blood for kell so I don’t know why the U.S. doesn’t. Maybe cost? Anyway, you definitely should not let this stop you from trying for the baby you long for. Your baby will probably be fine with such a low titer, and honestly, I doubt your husband is kell positive so your antibodies probably couldn’t hurt the baby anyway. 91% of the population is kell negative so your husband only has a 9% chance of being kell positive. Baby is only in danger if he is kell positive and he can only be positive if Daddy is positive. If your husband is kell negative (91% chance) then your pregnancy won’t be high risk and baby will be perfectly safe from the antibodies, even if your titer was in the thousands. If you get pregnant you can discuss your antibodies with your doctor and they would need to prepare blood ahead of time to match your antibodies, just in case you need a transfusion.

      • Thank you for your reply….
        results are in and he is Positive for Kell, could explain the problems I had with son #2 perhaps he is + and son #1 – who knows. Also I’m 1:32 not 1:1 perhaps I was not listening correctly. I guess knowledge is key. I’m actually in Australia and I was just going off what I have been reading online about the whole screening thing. I might have jumped the gun not sure where I read it but I’m annoyed either way. I have been wondering is it wise to donate blood if you are Kell + or have Anti Kell…. something for doctor next time we visit! Again thank you for sharing your story I’d say it’s helping a lot of people!

      • Wow, that is a surprise that he’s positive! And you are right, your second son must have been kell positive and you were sensitized during birth. His blood type would not have caused any problems during your pregnancy and birth with him though because you didn’t have the antibodies yet. It also has no effect on TTC thankfully. Anyway, even with a positive husband and a titer of 32 you can definitely have a healthy baby so don’t feel discouraged. Baby will just need more monitoring and possibly some intervention. Or you could still have a kell negative baby and a normal pregnancy. Also, you and your husband should not donate blood (or your youngest son, but I doubt he is wanting to donate blood anytime soon)

      • Bethany,
        I came back on here to reread your site after trying to fall pregnant for so long and seeing a fertility specialist I am finally pregnant. My Ob/Gyn booked me in for an appointment at a bit over 6 weeks. So I guess the adventure begins. It’s interesting how little general practitioners know regarding Anti Kell. I am thinking I should print out your site for my GP. I will keep you posted, knowledge is key. Thank you for your knowledge even though it comes from heartache.

  9. Hi there-
    I am so thankful for your post and so sorry for your loss of Lucy. I am 31 weeks pregnant and today at my OB appt the doctor was reviewing bloodwork and noticed that I tested positive for anti-kell antibodies at 18 weeks, 1:2. They quickly drew blood to retest and called my husband in for bloodwork. He tested positive, but my test today came back showing no antibodies. They are referring me to a MFM, but that won’t be until next week. My dad is a family doc and immedietly I called him and he had no idea what this was– has never heard of it (and neither had my doc). My dad called the MFM and he did a good job explaining much of what you said in your post. My question now is, is my child at risk if my bloodwork came back with no antibodies? I am going back and forth feeling at peace and being worried sick and I don’t know how I will get through the weekend. I am worried that if this baby is anemic and I am at 31 weeks, could I lose it at anytime without the IUT? My dad is feeling at peace based on talking to the MFM, but recommended I go to the hospital and get an Ultrasound (or maybe the MCA– i haven’t had one yet) to put my mind at ease. What are your thoughts on this situation?

    • So sorry you are dealing with this. So, if it were me, I would get in for an MCA scan as soon as possible, just because you are already 31 weeks and they discovered the antibody so late in the pregnancy. Once you test positive for the antibody it does not go away, ever, but sometimes it can be too low to titer and won’t show up. That doesn’t mean it’s gone, just means your titer has fluctuated or there was some variation in the testing, lab tech, etc. Titers fluctuate all the time. Your baby is probably fine because that is SUCH a low titer, but it could have been higher earlier in the pregnancy and you wouldn’t know since they weren’t monitoring you for it, you know? I really do think your baby is safe, but just to be sure, you should have an MCA scan. It is a non-invasive ultrasound that doesn’t take long at all and it could save your baby’s life. There is no good argument NOT to have one so if your MFM is not on board keep pushing for it or find a new MFM.

  10. I just want to thank you for share your experience, your blog is the only personal information I found in the internet about kell!, about 2 years ago we discovered that my wife had the kell immunization , our little baby is health and beautiful, she had 3 transfusions before and 2 more after birth!
    We live in Italy, near Venice, we found very expert doctors at Bologna, they made an excellent job, they monitored the baby every 3 days, and they made a wonderful job with the transfusions.
    Its amazing that there is very few information about this. Thanks again for sharing.

    • Wow, I am so glad your doctors were so proactive and took such good care of your baby. What a great blessing. I wish all doctors treated these pregnancies the same way. I am so thankful your daughter is healthy and alive! Thank you for sharing your story with me 🙂

  11. Hello sorry for your loss i am asking can this be harmful if u only find out you have anti k when u r 31weeks my neice just found out and we r a little worried

    • Yes, it can be dangerous. She needs to get in right away to have an MCA scan to check the baby for anemia. That should be the first step. Once the scan is done and baby looks good they can do the other tests (testing Dad’s blood to see if he is positive for the kell antigen) Do you know what her titer is?

  12. I contracted the anti-kell antibody in 1986 from a blood transfusion. I had 2 sons , one in 1988 and another in 1991. We lost our daughter Molly in the 26th week of pregnancy. There was not a lot known back then about this antibody, so thank you for shedding some light. I also have pernious anemia which complicates things even more. I have read conflicting reports about if I should be worried about my son’s future children as they are both planning to do in the near future.? It looks like they should be tested for the antibody at the very least. Any info or words of wisdom would be greatly appreciated.

    • Hi Donna, I am so sorry that you lost your daughter Molly. It is the deepest heartache. Even if your sons are kell positive it is unlikely that their wives will develop antibodies. Just to be safe, their wives can be tested for anti-kell antibodies sometime in the second or third trimester (all women are tested for it in the first trimester) but thankfully it is so rare to develop these antibodies. There have also been so many advancements in the treatment options available that most women with antibodies have healthy, living babies. If your sons are kell positive they shouldn’t ever donate blood, by the way.

  13. I am 17 weeks pregnant and I a
    Have anti kell antibodies and my baby s father is kell positive, this is my second baby, it looks like when I delived my first son my blood and his blodd mixed and I created the antibodies, I am super concerned because after reading your blog I complete understand how it wokrs and what must be done, but my obstretician and my maternal fetal dciror have no idea how to treat it, I have been telling them in a very nice way what I beleive they should do and they are telling me there is no way they will scan me weekly before teh 20 week and or are checking my titer levels avery week. i am trying to find another doctor but I am having a hard time, they are asking me for referals from my doctor and my doctor i telling me they akready sent me with the one I am seeing and I do not trust her at all. I am doing online searched and trying to call perinatologyst but it looks like nobody knows whta I am talking about. I need help, I live in South Florida

    • Hey Lorena, I just replied to your email. I’m so sorry you have to deal with your doctors and their reckless choices. You are right, you should be having weekly MCA scans since your titer is critical. Come find me on facebook and I’ll add you to the Iso Moms group and hopefully someone can help you find more experienced MFMs in your area.

      • I changed my perinatologist and the new one is understanding me more and today they have drawn my blood to be sent to Netherlands to find out if the baby is positive or not. I also found out today that my titer was 1:16 in 2014 after delivering my first son, it was 1:2 March 2017 when I found out I was pregnant and today April 2017 is 1:1. I do not get it, why my titer will go down? I had an MCA scan done today and it is normal I am 19 weeks 5 days and this was my third one, all of them normal. The new doctor was very happy with the information I gave her regarding the noninvasive test in Netherlands and she told me she will start doing with patients from now on trying to avoid the invasive tests.
        Thank you for helping me and my baby and a lot of future babies!

      • That is awesome Lorena! I’m so glad you found a good perinatologist and baby looked good on the scan. Did you get your blood results back yet? I’m still waiting on mine

      • QUestion for Lorena.. how much was the blood work to the netherlends.. i was quoted almost 2,000$. I’ll likely do it because i want to know… but sad insurance doesn’t cover more.

      • I only paid around $800
        The test was negative
        My baby was born September 6 very healthly
        Thanks to this post my doctor will star doing the test in Europe
        The experience between the lab and my doctor was so good! They were do glad I have them the info

  14. Hi, I am new to this group and so thankful to have found it. I’m really sorry to read about your families who have experienced heartbreaking loss due to kell and anti-kell. In the last few weeks I have learned that I carry anti-kell from blood transfusions after an auto-accident many years back and my husband just tested positive for kell. We discovered all of this as we are trying to conceive by my reproductive medical office during a routine blood-typing. My RE now suggests that we move to IVF and has informed me that there is now testing that can be done pre-insemination on embryos to determine is they are kell positive/husbands with one copy of kell have passed it so that the baby and pregnancy will be kell-negative. We are going to pursue this option next cycle once our lab confirms they can make the PGD test. I am very surprised there is so little information out there on kell and anti-kell and wish this was more routinely screened in all regards as it has lead to so much pain and loss, and that all options were explained to anti-kell women who are hoping to conceive. I wish everyone the best. Thank you for sharing and I wish you luck.

    • Hi Jackie, that is definitely a good option if you can afford it or if you were going to possibly do IVF anyway. Like you said, they can test the embryos ahead of time and find out which ones are kell positive/kell negative. They can implant only the kell negative embryos and then you won’t have to worry about the antibodies at all during the pregnancy and baby will be safe! Good luck! Would love to hear an update when you have one!

    • The results came back a few months ago and baby is negative so he has no risk, I am 36 weeks pregnant and c section schedulle for September 14th.
      Thanks ypu for everything and I will pray for you baby as well!

  15. Bethany,

    I just found out I am kell positive. Would like to join the fb group and can’t seem to find you specifically on fb. Let me know

  16. Oh my goodness, I’m so glad i came across this post. Im 15 weeks pregnant and just diagnosed with little c and E antibodies. My husband was positive for the antigen so were at higher risk for our little guy to be effected. So much of what I read online is not helpful and does not help me understand this, Your post made so much sense! My MFM also mentioned no shots for this because its rare and wouldn’t benefit enough people which was disgusting to me. Id love to join the facebook page with other ISO moms. I’m very scared but trying to remain positive. My titer is at an 8 which is still in the safe range for little c from what i understand. I’m being closely monitored but preparing for the worst. Thanks for your honest post.. it was so helpful. Im so sorry for the loss you went through…. no mom should have to experience that.


  17. Thank you for sharing your valuable story. Through genetic testing I just found out that I am Kell positive. My son (50% chance) is married and has one child and I know they will be trying soon for another. I have two questions. I’ve read that the babies blood and mom’s blood have to mix in order for mom to build antibodies. Isn’t this automatic due to pregnancy in general? Or does there need to be a c-section or some other trauma to mix bloods? Also, are kell antibody tests done routinely now? I don’t even want to worry my son and daughter-in-law if they are going to find out early in the pregnancy anyway and be able to pursue the same treatment.

    • So, blood does have to mix for the mother to build antibodies but most of the time women who are exposed to kell positive blood DON’T make antibodies. It’s not an automatic immune response. It is actually quite rare for a woman to become sensitized (as far as I know.) And it doesn’t take something traumatic for the blood to mix. I had an uncomplicated vaginal delivery with my second son which is how I became sensitized. I do think your son and daughter in law have an advantage now with the knowledge that you are kell positive. Even though it is a routine first trimester blood test, some doctors overlook the results even when they come back positive. It is also possible (but rare) for a mother to be exposed to baby’s blood during the pregnancy and she could start producing antibodies during the pregnancy after the first trimester antibody screen. If I were you I would tell my son but emphasize that there is no danger or complication yet, there are just some precautions to take. Then I would encourage him to get tested for the kell antigen now. It’s a simple blood test his dr can perform. If he’s kell negative they don’t have to worry about anything. If he’s kell positive he will know not to ever donate blood and he and his wife can take extra precautions with their next pregnancy. His wife can get tested now for antibodies if she’s curious about whether she developed them during her last delivery, or she can just wait and be tested after she’s pregnant. She could also err on the side of caution and have a second antibody screen done in the second trimester and maybe in the third as well. Thankfully, even if your son is kell positive it is very unlikely that their baby will be affected by antibodies. It’s still best to play it safe though so the extra blood tests and possible worry is worth it, in my opinion

      • Thank you for the explanation, you’ve answered ALL my questions. I feel better now about telling my son without scaring him…. his wife did have a c-section with the first, though. Hopefully he’s not positive and it won’t be an issue.
        I will tell all my children not to donate until they find out if they are carriers or not. Thankfully, I have never given blood since the first time I tried to donate at 18 and almost passed out. I used to feel bad about that, now I’m glad I didn’t pass this on to anyone! I will tell all my children not to donate until they find out if they are carriers or not.

      • Why should he not ever donate blood? Wouldn’t he want to so that individuals that are also Kell positive can have access to banked blood?? I am kell positive and also considering donating blood, so those like my self, can use this blood for transfusions.

      • Hi Mirissa, that is a good question! So, being positive for the Kell antigen and the antibodies are completely different things. I’m not sure if you are positive for the antibodies or the antigen. Anyway, people who are positive for the Kell antigen should not donate blood in the US because blood banks don’t screen for the Kell antigen when matching donor blood with recipients. So when a patient needs a blood transfusion the blood types are matched but the patient’s Kell status is not checked, nor is the Kell status of the donor blood. Roughly 91% of the population is Kell antigen negative. So, if a Kell antigen positive person donates blood, there is a 91% chance that it will be given to a Kell negative recipient. The recipient would then be at risk for developing anti-Kell antibodies which could cause major problems during future pregnancies. Other countries do screen for the Kell antigen and match it accordingly with the right recipients, but we don’t do that here in the US yet. Of course if the blood is being used for an intrauterine blood transfusion for a baby who needs Kell antigen negative blood, they carefully screen the donor blood to make sure the baby gets the right blood. Also wanted to say that it is totally safe for a Kell antigen positive patient to receive Kell antigen negative donor blood. No risk there.

      • Thanks for the response. I must have confused myself. I am still learning about this. I am Anti-Kell, or Kell-positive. I have the antibodies, discovered at the birth of my daughter). I’ve considered donating blood for those who may be similar to me. Is that not a good idea?

        Separately, we are planning for a second and have decided not to choose the IVF route. We are meeting with MFM with all of our questions to try and determine if this is something I can handle physically, mentally and emotionally.

  18. 20 wks i am anti Kpb and dad + homozygous for Kell antigen. Does this mean the risk to my baby are high. I have a MFM referal 16th March. Just can’t seem to find any definitive answers. I’m in the UK i just want to enjoy this pregnancy but I’m constantly on edge and worried. The info on your page is great and I thank you for that. I lost a little girl 13yrs ago due to sprom at 14weeks she was born at 29wks and lived for 12 hours. I do scared I’m going to loose another child.

    • Hi Clare, I am so sorry for your loss. I know that must make this situation even more scary and stressful. Have you joined our ISO Moms group on Facebook yet? We have a lot of UK moms. And just because your husband is homozygous it doesn’t mean baby will be affected. Did they test him for the kpb antigen or kell? I think they are different

  19. Hi, your website is really helpful- thank you. Can I clarify is Kell positive dangerous if both parents have it? My daughter was stillborn in Oct 17. I had Kell antigens in pregnancy. But apparently both my husband and I are Kell positive so I didn’t develop the antibodies and her death twouldn’t have been caused by Kell. Does that fit with your understanding?

  20. Thank you for sharing your story and providing easy to understand information about this situation. You’re right, there is not a lot of information out there. So happy things have turned around okay and thank you again.

    • No, if you have the Kell antigen (I’m assuming you’re a woman?) then there are no risks for your pregnancy. It’s the antibodies that can be dangerous to the baby. I feel thankful now that my daughter has the Kell antigen because she won’t have to go through what I went through with her

  21. Thank you so much for sharing your story! You have helped many, I’m sure! I am currently a 22wks pregnant anti-kell carrier. Just had our 3rd biweekly MCA scan yesterday. MCA has increased to 1.4. My MFM rechecked my titer (previously 1:16). I won’t find out the results until Monday. She went ahead and scheduled me for a repeat MCA US a week later. I am so nervous! It has hard to find good information on this subject! I’d love to be directed to any sources you found helpful.

    • Hi Jessi, since your titer is already over critical you should be having mca scans at least once a week already. Your titer can’t really tell you much, unfortunately. A higher titer doesn’t mean baby is more affected and a lower titer doesn’t mean baby is less affected. The mca scans (done weekly for the rest of your pregnancy) will show you how much or if the antibodies are affecting your baby. 1.4 is close to 1.5 but thankfully still under the transfusion level so baby is doing ok😊 A lot of times MoMs fluctuate so hopefully baby’s numbers will be lower next week. If you get higher than 1.4 next time, but are still under transfusion level, maybe talk to your mfm about doing scans twice a week

      • Thank you so much for the fast response! I’m praying it goes back down but definitely agree with the weekly MCAs from this point on.

  22. I can’t tell you what a relief this was to me. I was recently told I am anti-kell positive. Which makes no sense because my husband (and only man I have ever been with) is kell antigen negative, and I have never received a blood transfusion. So, it makes no sense as to why I would be anti-kell positive if I have never been pregnant with a kell positive baby, had a blood transfusion, or done any type of drugs. I just had my first appointment with my MFM at 15 weeks. I had no idea why I was even going because my original OB didn’t know enough about this situation to give me any information. I went alone thinking it would just be a quick check since my husband tested negative. Instead, I left in tears because I was being told it was likely my husband’s test was a false negative since I have never had a blood transfusion or positive kell pregnancy. Since yesterday, I have been trying to read as much as I can about this, but most reading materials online are all from medical journals and are hard to understand without a medical background (which I do not have). They are retesting my blood to see if mine was a false positive. I am hoping that is the case or that my husband’s test is not wrong and I somehow got a blood transfusion without knowing. My titre was 1:1 at around 9 weeks. I haven’t received any other results since. I was told I wouldn’t be able to have any more children after this baby boy I am currently carrying because the risk would be too great. Reading your story, though heartbreaking for Lucy, does give me hope that this doesn’t have to be my only child. I have been trying to figure out if I can be anti-kell positive through any other means besides blood transfusions and pregnancy. I am O- so I give blood on pretty consistent basis, so I was worried that maybe I had been stuck with a dirty needle. I am just still not sure if that really is a possibility. But, thank you for sharing. I am seriously so grateful I found this.

    • Hey Taylor, I’m so sorry you are going through this. First, please don’t listen to whoever told you that you can’t have more babies after this. That is completely untrue. In order for your baby to even be affected by your antibodies you would probably have to have a higher titer, your husband would have to be Kell positive (9% chance) and your baby would have to be Kell positive as well. After all of that, even if your baby was affected by your antibodies it doesn’t mean he won’t be born healthy or that you couldn’t go on to have more healthy babies afterwards. Your situation is rare but not unheard of. I know several women who still don’t know how they became sensitized. Are you sure that your husband was tested for the Kell antigen and not the antibodies? It’s a common mistake for them to test the partner for the antibodies instead of the antigen. Try to get your husband’s actual blood test results to see if they did the right test. If you’re not sure you can email me a photo of his results and I can tell you if they did the right test or not. You can also come join our ISO Moms group on Facebook if you want more information. It’s by far the best source of info on this condition available

      • Thank you so much. I just requested to join. My doctor may have just said that it’s may not be smart to have more kids and in my panic brain I interpreted as I can’t have more kids. I was so overwhelmed I honestly couldn’t tell you her exact words. But I know she is experienced with this because she has patients just like me right now. I just received my second test results, and I am still positive. I’m not sure what the titers where for that one yet. My husband was tested for the antigen. My doctor yesterday made sure of that before she went on with our discussion. Thank you so much for referring me to the group and replying so quickly. I already feel more at peace.

  23. Thank you for sharing Lucy’s story and your journey. This was the only article that I could find that had any positive outcomes with Kell and I can’t tell you how grateful I am that you had the courage to share your experiences and education. I am currently pregnant with a little baby boy named Wyatt. I knew I had the antibody since my 8 week visit, and we knew my husband was heterozygous at 11 weeks. We did amnio at 15 weeks and our boy was showing the Antigen. So We are scheduled for our first transfusion tomorrow at 23 weeks. I know they are supposed to tell you all the bad things that could happen during the procedure, but it makes it so scary. Please keep us in your prayers and I would love to join your Facebook group for support. Thank you again and God bless.

    • Hey Jessica, I’m so glad my story could help some. Definitely come find me on Facebook (Bethany Weathersby) and I can add you to the ISO Moms group or you can search for the group and ask to join. Lots of women have been through IUTs and can give you encouragement and support. I will definitely be praying for you, Wyatt and your doctors!

  24. Hello my name is Sarah.
    I just want to say thank you so much for this very detailed and informative article. I just found out yesterday that I am anti kell. I never knew anything of this and couldn’t believe how it was presented to me. My Dr left me feeling completely hopeless and an emotional disaster. I left work yesterday afternoon and spent all evening trying desperately to find answers only to find horror stories which in turn made things worse. I’m currently 14 weeks and 3 days pregnant with my third child. I have 2 perfectly healthy children 8 years and 4 years old. I was never told anything about this condition in either pregnancy I did suffer preeclampsia with both though. I found out today my titer is at 1. The Dr I talked to today told me that that’s a good sign? He said that’s the lowest a titer can be? I was referred to a specialist close to home and I’m waiting on my first appointment. I’m wondering how this will turn out. I tried for 7 months to conceive this baby and I just want some kind of hope and reassurance things will be ok. I want my husband tested as well. Do you know how long it takes to have that test done to see if he’s kell positive or negative? I would appreciate any more information or advice you have on the subject. I don’t have a Facebook or social media. I do have email and would not mind at all if you emailed me anything you have.

    • Hi Sarah, the first thing I want to say is that you absolutely do have hope for a healthy baby! I know it’s hard to shift from your previous pregnancy experiences to “high risk pregnancy” but with the right monitoring and treatment, your baby should be fine. Most Kell pregnancies don’t need intervention and end with healthy babies. The best thing you can do to keep your baby safe is to educate yourself regarding the disorder and ask questions about things that you don’t understand, and make sure you are receiving the appropriate medical care. You’ve already been researching and now you are asking questions and learning about the disorder, so you are doing a great job advocating for your baby already! To answer your questions- Yes, a titer of 1 is very low ( the lowest titer is technically “undetectable” so it can actually be lower than 1.) The critical titer for Kell is 4, which means baby in utero shouldn’t be affected by the antibodies if the titer is lower than 1, but with Kell there is still a risk of baby being affected even with very low titers. It’s rare, but possible. For some perspective, my Kell titer at the moment is 2,048 (I’m not pregnant, by the way.) Your husband can be tested now by his regular doctor or your regular OB, no need to wait until your MFM appointment to do that. They need to do a Kell antigen phenotype on him and the results should come back within a week or so. If your previous kids are by the same father and you’ve never had a blood transfusion, you can assume that your husband is Kell positive, but it’s still important to have him tested anyway. When you meet with you MFM, ask about monitoring- will they just check your titer with blood tests or do they plan on doing MCA scans to check baby for anemia as well? Feel free to email me if you want

      • I had tried several times to post new comments but it did not work and I emailed you yesterday since the site wasn’t working. I want to first of all thank you so much for talking to me, and all these other women out there that so desperately need answers and a clearer understanding. You and little Lucy are true blessings in my life. I can’t express how grateful I am to you for being so knowledgeable in this subject. I honestly had never herd of this or even thought something like this could exist. You have given me hope and I’m grateful to you. I see a specialist in San Antonio Texas this morning and am hopeful for more answers. I will ask for them to test my husband. I have an 8 year old boy from a past relationship and my pregnancy was normal other then developing preeclampsia at the end. My daughter is 4 almost 5 in November and my husband is her father. I don’t know how I became sensitized to this but I can guess my daughters birth 4 years ago? I did receive a blood transfusion in 2011 when I had a bi lateral hip replacement. My son was only 4 months old. I was given several blood transfusions. Is it possible I became sensitized from that? If so wouldn’t my prenatal screening show anti kell when I became pregnant with my daughter. Do you think I can rule the transfusion out and guess that is was probably in 2014 when I gave birth to my daughter? Which is more likely? I’m so scared for tomorrow and don’t know what to ask other then having my husband tested and my titer tested again and to check baby. I have cried every night since hearing this news. I’m so sorry you went through this multiple times. I could never do this again. Please pray for me tomorrow. If you have any advice please give it. Again thank you and god bless you and your beautiful family.

  25. Hello,

    Thank you so much for writing your story! I just received a call from my doctor today telling me I’m anti kell positive so searched the Internet frantically today. I came across your story and it has made me feel so much more at ease! I now feel like I can breathe and just take it day by day now.

    How long did you wait in between pregnancies after Lucy to try again? Also, did you have to have c sections or were vaginal births an option with the anti kell antibody?

    • Hi Samantha, sorry I am just now seeing your comment! We started trying for another baby about 3 months after Lucy died. We weren’t successful conceiving, so that is why we tried the adoption route (which didn’t end well.) Then we found out we were pregnant with Nora and she was born about two and a half years after Lucy was stillborn. I had Callum two years after Nora, and I had August almost three years after Callum.

      You don’t have to have a c-section just because you have anti-Kell antibodies. Just like any pregnancy, it all comes down to what your doctor thinks is safest for you and the baby. With my daughter Nora, I was induced at 37+6 weeks after her five intrauterine blood transfusions. We had to time the delivery on her last transfusion. I had an easy, quick vaginal birth with her. My next baby, Callum, went into distress at 34+4 weeks and had to be delivered by emergency c-section and he did go into distress because of the antibodies/fetal anemia. My last baby was delivered by planned c-section (also timed by his last transfusion) because both my OB and MFM felt like it was the safest choice for baby and me.

  26. I have a question 🤔
    I recieved a blood transfusion that has now made me positive for kell antibodies so does this mean I can never have a transfusion that is kell positive again?
    Sheri Clarke

    • Hi Sheri, sorry I am just now seeing your comment. Yes, if you have Kell antibodies, it means anytime in the future if you need a blood transfusion, they must find donor blood that is Kell antigen negative. If you receive Kell antigen positive donor blood it could cause a transfusion reaction.

  27. Thank you so much for this page! I just received the news on Friday afternoon that I tested positive for Kell, only to be told no doctor was available to explain what it meant until Monday morning, which was obviously frustrating. They have already referred me to a MFM. I did have a blood transfusion after my first pregnancy, so I’m hopeful that the baby will not be affected by this. I have requested to join the Facebook group. Again, thank you for the information broken down in a understandable way, Google is a scary place!

    • Hi Megan I’m so happy I could help! That is great that you already have a referral to an MFM. Your next step should probably be to get baby’s father tested for the Kell antigen and if he is negative (about a 91% chance) then baby is completely safe from your antibodies.

  28. Hey
    I just found out that i have the Kell antibodies and i’m freaking out could really use all the information i can get. Do you know what is the phenotype of a negative person and would K+k- be different than
    K-k+ because my husband result is the second one and i don’t know what does it mean is positive or negative and do you need to know what kind of antibodies do you have like big K antibodies or small k antibodies ?

  29. Hi,

    I am about 4 weeks pregnant and just found out I have anti K bodies, I had it during my first pregnancy and was very closely monitored by the hospital I was referred to and now have a very healthy three year old. I have had a miscarriage since but am now pregnant again and am being referred to the same hospital again to be monitored, my titre is 1. Odd thing is we don’t know how I got the K antibodies as I have never had a blood transfusion.

    Fingers crossed everything goes well with this pregnancy as well. This page really gave me a better understanding and I wanted to say thank you and God bless you, you are helping so many women and families understand and educating us.

    Thank you!!

    • I’m so happy that my story has been helpful to you and that your first baby is a healthy 3 year old now. I’ve actually known a few women who have anti-K antibodies and have never had a blood transfusion and the antibodies were discovered during their first pregnancy. So strange! Anyway, we would love for you to come join our support group on Facebook if you would like to connect with lots of other women with antibodies from all over the world. The group is called Antibodies in Pregnancy: An AHF Support Group.

  30. Thank you for this article very informative. I wasn’t made aware until a few hours after I had my son ( second pregnancy) that I was positive. I had blood work throughout my pregnancy which showed I was negative. I don’t get how this could of happened ? Should I be worried something is wrong with my son? I can’t seem to find much on this.

    • Hi Kelsey, quick question, how old is your son? If he was born recently they should be checking his bilirubin and hematocrit/hemoglobin to monitor for high bilirubin and anemia. Both issues are completely treatable if monitored closely and treated in a timely manner. Regarding your positive antibody screen, women can actually develop antibodies at any time during a pregnancy or soon after birth. It is normal for some of our baby’s blood to leak out into our own body during pregnancy and during delivery, which can cause an antibody response.

  31. I have 2 children 11 & 9 healthy only issues during pregnancy was Hyperemesis gravidarum. I had an ectopic pregnancy June 1st of this year and has to receive blood transfusions and through that I contracted (not sure if this is the right term) kell positive antibodies. I am 13 weeks pregnant and just found out 6 days ago and at 1:7. My ob didn’t really know about it so he’s referred me to another OB at a high risk center on Dec 10. Is this where I should be going or do I need to specifically ask for an MFM and should I be pushing for a quicker appointment? I left very confused and got home and googled smh. I haven’t been able to stop sporadically crying and reading. I am so scared to lose another when I haven’t even had time to grieve the 1st. (I went to my OB to get on BC again and found out I was pregnant)

    • Hi Cassondra,
      I am so sorry for your loss in June and that you now have to worry about these antibodies. The first thing I want you to know is that your baby will probably be fine! Truly, I am not one to give false hope so I wouldn’t say that if I didn’t believe it. Odds are, (91% chance actually) the baby’s father is Kell negative which would mean the baby is Kell negative which would mean your baby is completely safe from your antibodies. Your baby is only at risk if the baby’s father is Kell antigen positive. Only about 9% of the population is positive for the Kell antigen. If he is negative, your pregnancy won’t even be considered high risk because the baby can’t be affected at all by your antibodies. If your husband is positive for the Kell antigen there is still a chance baby is Kell negative. If baby does happen to be Kell positive, you will need weekly MCA Doppler ultrasounds to monitor for fetal anemia. If baby does get anemic your MFM can treat the anemia with blood transfusions. However, your titer is actually quite low so I would be shocked if your baby did need intervention if he happens to be Kell positive. It’s possible, but most women I know with a titer as low as yours don’t need IUTs.

      The first thing you need to do is have your husband tested for the Kell antigen. That can be done my your OB, or his regular doctor. It’s a simple blood test. That will show if your baby is possible at risk or not. I think you should ask your OB if the doctor he is referring you to is a maternal fetal medicine specialist. If they are, then Dec 10th is fine. No need to see them earlier. If your baby does happen to be Kell positive they will need to start weekly scans between 16-18 weeks. Also, come and join our wonderful support group on Facebook called Antibodies in Pregnancy: An AHF Support Group. And you can find tons of resources at

      And remember, this is a TEMPORARY disease and a TREATABLE disease, so your rainbow baby has so much hope for a long, healthy life ahead!

    • I also have 3 children (31,28 and 19) I developed Anti Coa (Colton) after my first, and Anti Kpa- didn’t show up til my 3rd child. All 3 of mine were full term babies weighing 9lbs, 9.2 and 7.9lbs.

  32. Thank you so much for all the information here! It’s one of the only resources I’ve found. I am 22 weeks pregnant and just had positive lab tests for Anti-S, Anti-K, Anti-Jkb, and Anti-C. All the titers are extremely low, so we will monitor it for now. Neither my husband nor I have had past blood transfusions so the doctors are not sure where this could come from. My husband is awaiting test results right now. Have you heard of other cases like this? I can’t find anything that explains how I might have developed these antibodies if my husband/the baby don’t have the antigens. Based on other replies here, it seems like it’s a good thing if my husband is negative.

    • Hi Amanda, first of all I am so sorry you have to deal with all of these antibodies! I do know a lot of women who have multiple antibodies. It seems like those of us who develop an antibody are more likely to develop other antibodies. Maybe our immune systems are just overreactive? Anyway, I also have anti-K and anti-Jkb. I know several women with anti-S and lots with anti-C. Is this your first pregnancy? If you have been pregnant before, I would guess that you were sensitized during that pregnancy and your husband is S, K, Jkb and C positive.

  33. I am so sorry about the the loss of your little Lucy. I do find comfort in your story. My daughter Anastasia and her youngest daughter Addy experienced their own “Kell Journey” 12 years ago. While both mom and baby girl Addy are fine it was such a wild and scary experience.

    Thanks for sharing your story. I donate my blood any time I am able. I will keep your “littles” Nora and Callum along with Addy in my prayers when I donate in several weeks.

    As a cancer survivor, I have found that helping folks can be very healing. Thank you again for sharing. May your strength remain strong and your family healthy.

    Grammy Lin. 🙏😘

  34. I thank you so much for your insightful story. It was the answer to many questions and fears I had about this Kell antibody.
    Are you in California? What is the name of your MFM?
    Thanks again from the bottom of my heart.

  35. You have no idea how uplifting your story has been for me. I tested positive for the Kell antibody. I never had a blood transfusion and still waiting for my husband’s test results to see if he has Kell positive blood. Just knowing that the treatments worked for you gives up hope.

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