* 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.
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 three anti-Kell 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 anti-Kell antibodies that tried to kill her in the womb. My last baby, Callum, was born at 34 weeks 4 days and is now a healthy toddler. Over the past six years I have done a lot of research and asked a lot of questions, so I have a much better understanding of this disorder now. 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 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. Somehow, we always seem to get the wrong 50% because our last four 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 very anemic and eventually can cause fetal hydrops or even death if the fetal anemia is untreated. Thankfully, with the correct monitoring the 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 1:4 it becomes critical for the baby. This just means that the antibodies can affect the baby at that level. My titer was 1:1,024 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. Now that I’m not pregnant, my titer is 2,048, the highest it’s 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 three year old like I mentioned before. My son, Callum, also received the correct monitoring and treatment and is 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 occurred. 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 14 or 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 five IUTs. My son Callum had his first MCA scan at 14 weeks and had 3 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. 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 baby Callum 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 do an IUT procedure on you.
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. With Nora and Callum 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’s another similar disorder called Rh incompatibility that is much more common. Because it’s so common they developed a shot called rhoGHAM that they can give to the mother before she gets sensitized 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 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: firstname.lastname@example.org 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.