* If you are dealing with anti-Kell antibodies and are searching for information, don’t be freaked out 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 two anti-Kell pregnancies in the past three years 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. Over the past three 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 and possibly Liam all are positive for the Kell antigen. About 9% of caucasians are Kell positive. I’m not positive for Kell, 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 positive blood) some of his blood leaked out into my body. 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 given 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. 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.
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 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 three kids have all been Kell 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 her blood. This makes the babies very anemic and eventually can cause fetal hydrops or even death. Usually these babies have at least an 80-90% chance of survival because the mother’s antibodies are not as aggressive as mine were. The way they measure the anti-Kell antibodies is something called a titer (pronounced “tight-er”.) When a mother’s titer reaches 1:8 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.
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. Because of this, Dr. Moise believes that a subsequent pregnancy would be equally as dangerous as it was for Nora and Lucy. 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.
The way they treat these babies is to monitor them very closely and give the babies an intrauterine blood transfusion if they get anemic. Doctors can tell when the baby starts getting anemic by doing an MCA 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 will 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 15-16 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.
When an IUT is performed, the doctor basically sticks a really long needle through the Mom’s belly into the uterus and (hopefully) 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. It’s not as good in the belly, but still helpful. They were able to hit Lucy’s umbilical vein and give her lot’s of good blood. Because she was so anemic they also went in a second time and put extra blood in her abdomen. It should have been a huge success, but she died a week later. We still are not exactly sure what happened. One doctor really thought I had had a fetal maternal hemorrhage, which is random and can also cause fetal anemia. Most doctors think Lucy was just too sick by the time they did the transfusion and they couldn’t save her or something went wrong during the IUT that caused her to bleed out. Dr. Moise thought that my antibodies were just too aggressive for Lucy to survive without early intervention.
With Nora I started plasmapheresis and IVIG around 10 weeks. These treatments were able to protect Nora from my antibodies until she was big enough for a safe IUT. She had five IUTs by the time she was born. When Dr. Moise performed Nora’s IUTs he always put blood into the umbilical cord and into the belly. This was so that the blood would get to Nora immediately through the umbilical vein and then slowly over several days/weeks as her body absorbed the blood in her belly. Her first IUT was at 24 weeks and I believe her last one was around 35 weeks. 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. Usually, if there is a complication from the IUT it happens within the first 24 hours after the procedure.
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 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 1:8 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
- Definitely join our ISO-Moms group on Facebook to meet other women who have been through this type of pregnancy, who can answer any questions you have. It’s a secret group, so you have to become my friend on Facebook in order to be invited (you can unfriend me after I add you to the group if you want.) My name is Bethany Weathersby, so come find me if you want to join! Just be sure to send me a private message explaining who you are.
- Feel free to email me 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.