A little bit about the Kell positive blood type

In Blood Will Tell I talked about the theory that Henry VIII had a Kell positive blood type, but in my quest to prevent innocent readers from slipping into an over-science coma I didn’t go into deep detail about it. . This post will provide a tad more information as to what it is exactly and how it is transmitted.

To have Kell positive blood means you have at least one of the Kell antigens on your red blood cells. This is in addition to the ABO blood groups that most people know about. There are apparently quite a few antigenic things that can be running around on the surface of your red blood cells. Who knew?

The funny thing about a Kell positive blood type is that the Kell antigen is passed on by a dominate gene, but even though it is dominate it is rare; less than 10% of the people in the UK have it. How can that be? Wouldn’t dominate genes … dominate?

Not necessarily, as it turns out.

Do you remember the Punnett Square from middle school biology classes? Okay, let’s call the Kell positive allele “K” and the Kell negative gene “k”. Everyone would have two of these genes, so people with Kell positive blood are either “KK” or “Kk”, and people with Kell negative blood are “kk”. Now, what would happen if a Kell positive person reproduced with a Kell negative person? Their children have the potential genotypes of:

Kk Kk
Kk Kk


Kk Kk
kk kk


We know two things from these squares and the fact Kell positive blood is rare. First, people who are Kell positive are most likely to be Kk instead of KK Why? Because there is a more than 90% chance that one of their parents was Kell negative, and thus had only k genes to bring to the party. Secondly, when Kell positive people with the typical Kk genotype reproduce with one of the Kell negative (kk) majority, each child has only a 50/50 chance of being Kell positive.

Let’s look at the hypothetical example wherein a Kk/kk couple has four children to see what can happen:

1) They have no K postive offspring. Now, we’ve all met families where all the kids were the same gender, so you know 50/50 doesn’t mean it will always split down the middle between two outcomes. Thus, all four  children could be kk and Kell positive blood would disappear from their genetic line. Unless one of the offspring reproduces with a Kell positive partner (which is a less than 10% chance) no grandchildren will be Kell positive, and so on forevermore.

2) All four kids are K positive. If all four children are girls, and they each are Kk, then Kell positive blood is very likely to show up in the grandchildren. However, if all four children are boys then the Kell gene is much less likely to turn up in the grandchildren, because every pregnancy after the FIRST one will only survive if it is Kell negative (kk). So if every boy grew up, married, and had 4 kids himself … then no more than 4 out of the 16 grandchildren could possibly have the Kell positive gene. Since there is only a 50/50 of a first born getting the K gene, maybe only 2 out of the 16 hypothetical grandchildren will be Kell positive. Or maybe none of them will be.

Basically, every time a Kk person has a male child, the odds of the K gene making it to the next generation is lessened. (Well, it used to be like that before modern medical treatments that will keep a Kell positive fetus alive inside a Kell negative mother. Kell may become more common now. Ask me again in 150 years.)

Moreover, random chance can make a dominate gene go bye-bye even when the dominate gene doesn’t cause the death of many offspring who inherit it. Take brown eyes and blue eyes, for example. For simplicity’s sake we’ll say brown eyes are “B” and blue eyes are “b”. This means we can use the Punnett square again and see the genotypes of the offspring of a brown-eyed person (BB or Bb) and a blue-eyed person (bb).

Bb Bb
Bb Bb


Bb Bb
bb bb

Let’s say mom has brown eyes of BB and dad has blue. Every one of their kids will have brown eyes because of the B, but they will all be carrying the blue b as well. If mom’s brown eyes are Bb, then some of the kids might be blue-eyed, but the brown-eyed kids are all going to be carrying a recessive too. See? Once you get a bb in the mix those little b genes are lurking in every gonad. If those offspring marry blue-eyed (bb) people, then more of the grandkids will be blue-eyed too. Once a person has expressed recessive genes, there are NO dominate genes to pass on to their kids. Dominate browns can easily be hiding secret blue genes (insert blue jean joke here) but the brown B is gone once the recessive have the field. If two couples, let’s name them Ted (BB) & Alice (bb) and Bob (bb) & Jane (Bb), have children who marry each other then it is possible that all their grandchildren can have blue eyes in spite of the fact that two grandparents have the dominate brown-eyed gene. Of course, all of them could have brown eyes – it depends on the roll of the genetic dice when Mr. Sperm meets Ms. Egg.

There you have it. A very simplified version of how a dominate gene (especially one that is harmful under certain conditions) can wind up being in only a small minority of a population.

It really was just bad luck that Henry (in theory) had a Kk genotype. How do we know that if he was Kell positive, Henry had to be Kk and not KK? Because the New Year’s Boy survived for a few weeks and Mary lived to adulthood. If the King had not had a “k” gene to give them, they would have died in utero or a few hours after their birth like their poor siblings did. QED – Henry had a Kk genotype.

But how did Henry get that Kell positive gene? Well, tune in next post for the exciting adventures of Genealogy Quest!

123 thoughts on “A little bit about the Kell positive blood type

  1. I contracted the Kell antibody because of a blood transfusion I had after my 1st pregnancy which was a c-sec. 2nd pregnancy I had kell antibodies but since Dad is Neg and my pregnancy went on as normal. My question is will my son have any Kell at all? I would hate for his future wife to go through the scare I had, or since Dad is Neg & my pregnancy was “normal” is my son kell free?

    1. The good news is that a simple test will tell you if your son has it … and the better news is that I think it is highly unlikely. The Kell antibody was introduced into your system, and Daddy is also negative, so as far as I can tell there is no way your son inherited the genes to produce Kell antigens. QED — he’s Kell negative. Hope that helps!

      1. Thank you very much, I had quite the scare and was so mad about the whole thing . Thank Goodness all is ok, but now I don’t think I can donate Blood anymore which is sad as I am
        O-Neg….I appreciate your response have a wonderful day.

    2. If you and the father and both kell neg then your child will be kell neg. No worries! I had a similar experience as you did and I had to explain this to my doc or they wouldn’t let me have a home birth. I too had a tainted blood transfusion because the hospital over dosed me on pitocin during my 1st birth which caused a hemorrhage. Hence I said no more hospitals with my second birth!

    3. I’d be worried about the antibodies that you contracted not the antigen Kell

  2. I had two miscarriages a year ago. And after my second one (a week later) I had blood work done and it came back that I had Anti Kell. But my levels of it were too weak to show up on the titer level. Well, here I am a year later and I had blood work done the other day and my blood showed NO kell. My OB says my blood is normal. Is that possible? Or if I get pregnant again will it come back?

    1. I am not a medical doctor, but I will give you all the information I have. Just remember that my opinion is likely to be inferior to the doctor’s on any point of difference.

      First, I think s/he is correct about your blood work being normal. If there is no Kell positive fetus/embryo in your uterus then your body won’t be making the anti-Kell stuff to attack it with, so there shouldn’t be enough to show up.

      As for the next pregnancy … luck will play a big part of it. My hubby is a type 1 diabetic, and (although the public doesn’t seem to know this) blood sugar levels effect spermatogenesis. That means the partner of the diabetic man is more likely to have miscarriages because the sperm that fertilizes the egg may be “broken”. I knew this, and understood it rationally, but when I had two miscarriages in a row I was still devastated because the heart tends to ignore the brain. Thus, I do have some inkling of what you are going through and you have my deepest sympathy.

      I wish I could tell you it would be a-okay from now on but it will depend on several factors. The good news is that your husband is EXTREMELY likely to have a non-Kell gene as well as a Kell gene to give an embryo. If you get a non-Kell sperm then (if all else is normal) you will have a healthy pregnancy and a hearty little baby at the end of it without any big medical interventions. If you do get a Kell positive fetus then there ARE things the doctor can do to save the pregnancy. Just make sure s/he remembers/knows your last pregnancy had this issue. There is unlikely to be any insurmountable obstacles preventing your from having children … it may just take longer and be harder.

      After losing two pregnancies, I was blessed with three healthy babies in a row. I sincerely hope all of your subsequent pregnancies bring you such joyful results as well!

      1. This response is inaccurate. Beings you did NOT mention a transfusion it is likely your husband is a carrier.

        You should now take the advice from a MFM vs an OB. Once you are sensitized you can be too low to titer but should you get pregnant again w a K+ baby chances are your body will will have the same reaction. This exact scenario actually happened to me. Bc my antibodies no longer titered my OB did NOT want to do an amnio to determine if my baby was K+. I ended up demanding one. He was K+. By the time I got to the MFM 20ish wks he had to b transfused three days later bc of severe anemia. He would have died had I taken that advice.

        1. I’m also going to add a futer amnio should be done by a MFM @ 15-18 wks. At that time the MFM usually would do an MCA to check to see if baby appears anemic before the results come back as transfusions can happen as early as 16 wks. Kell is the most agressive antibody. If you get pregnant again you need to be referred to a high risk doctor by 12 wks. My doctor was under the impression all they would do was an early delivery starting at 25 wks. Thus it is critical this is passed off to a dr who specializes in this condition.

    2. I was diagnosed Kell positive when I was in my 20.’ My wife at the time had 6 miscarriages. All 6 was during the first trimester. It took a toll on our relationship.

      1. I am so sorry. Did her Ob/Gyn not test for Kell antibodies in her blood after the third miscarriage? (Sadly, two losses in a row are common; docs don’t usually ‘worry’ until the third.) Also, multiple miscarriages could have been because of a physiological issue in the mother, as well. Multiple pregnancy losses are agonizing to go through, but more common than people realize. Again, I am sorry for your many losses and I hope you have reproductive success in the future.

  3. Thank you for the advice Kyra! And that’s awesome you have 3 precious babies! Thanks for the positive thoughts as well 🙂 will keep you posted!

  4. Help. I am pregnant and diagnosed as having the anti-Kell antigen. We have been trying for years to have a 2nd baby, I have had several misscarriages so those were probably Kell positive babies. I am terrified but there are no support groups for Mom’s struggling with this since it is so rare. Looking for a shoulder to cry on while I go through this process.

    1. Dear BirdNerd,

      This got caught erroneously in my spam filter. I am so sorry about the delayed reply. I sincerely hope this reply finds you well and delivered of a healthy second child!!!!!

  5. Okay, I’m trying to remember science in middle school, having a tough time. So of you are Kk, then are you positive or negative? We are waiting for the results of my husbands bloodwork, I have Kell and Kidd antibodies. Really wish they would screen blood for this when someone donates, it is scary for women to have to go thtough this. I have been wondering if the tables could be turned, could the father produce a K positive baby and mom be k negative. Would the baby’s blood attack moms blood? Not sure why this came to mind but it dis, perhaps I’m trying to occupy my time while we wait for the blood work. I wish we had the $ for the full bloodwork for my husband, as we are only finding put of he is positive or negative for the antigens. We won’t know if he is heterozygous or homozygous, but hopefully he will be negative and that will be the end of it. What I am also wondering is are the Kell antibodies only detectable if the baby in fact has the antigen, or are they detectable even when basically dormant.

    1. I wonder if there is anyway that we can change this? I too became anti-kell from a blood transfusion. And I am now pregnant waiting in test results. I have some friends that I am trying to work with to petition some how to get blood Donors screened for kell. Hoping that it will help young girls/women of childbearing age. It could be prevented if they would just screen.

      1. I agree with the petition. I’m 34 years old. At 25 I gave birth to my first child and had a blood transfusion where I than became KK positive Kell antigen. I didn’t find out until i was preganat with my second child five years later. My doctor explained my problem to my husband and I, where I cried until his results came back negative. For a few years I’ve been wondering how many other women.. But after reading this I can’t believe how this problem it has become a nightmare to many moms.
        Debbie from NY

        1. I’m 35 weeks and I found out about two weeks ago that my original bloodwork was positive for the anti kell. After my first born I had a transfusion that obviously contained the Kell antibodies. Today my husbands blood work came back as negative just as your husbands did. Was that the end of the drama? Did the doctors have to take any extra special precautions or anything like that? I do have slight anemia which they believe is caused by the kell. I feel like even if the baby is negative and so is my husband that there could still be problems with myself?

          1. I will love to hear this answers to her questions those are the exact questions i have my self 🙂 thank u.

          2. Yesterday was the scariest episode my ob detected antibodies in my blood with a K positive . I had a blood tranfussion a year ago. I’m currently 33 weeks pregnant. They did blood work for my husband he turn out to be k negative. Should my worries stop or is their any threats to my baby girl?.thank u so much

          3. Okay, remember that I am NOT an MD and thus your OB/Gyn outranks me by a factor of 20. However, if your husband doesn’t have the Kell gene to give your baby, then your body should have no reason to attack her. At 33 weeks, she is with the range of viability so even if your body starts attacking they can induce your labor and ‘rescue’ her from a hostile uterine environment. It sounds like everything will be good, though, so try to stay calm. Stress can also hurt you and the baby. I hope it all works out perfectly!!

          4. If your hubby has no Kell gene to give your baby, then your body will have no ‘reason’ to attack the fetus, and all should be well. Pregnancy is complicated though, so I cannot ‘promise’ you no issues at all. However, your should be safe on the Kell front.

  6. Never mind about the question, I asked it wrong can a Kk pass only positive onto a child or can they still pass the negative too? Maybe it is on your post it is pretty late.

    1. If your husband is Kk then the babies could have the Kell antigen. If he is KK then they will definitely have the Kell antigen. If he has kk, then it’s all clear because he cannot give any offspring the Kell antigen gene. If it is a first pregnancy, then the mother’s body will not attack the fetus even if it is Kell positive. However, any subsequent pregnancies will be threatened if the fetus is Kell positive. If the mother is Kell positive but the dad is not Kell positive, then the fetus will be unharmed by the mother’s body either way. I hope you get good news!!

  7. I have just found out that I had K antibodies in my blood tests in my second pregnancy. I didn’t have them in my first and haven’t had a transfusion. When my husbands blood came back, he is kell negative. He is 100% definitely the father. How have I got these antibodies?

    1. Well, my first instinct is to wonder if you got a false positive or if your husband got a false negative. If you had the antigens, it would just mean you are Kell positive and it would pose no threat to your pregnancy, but antibodies mean that your blood has been exposed to the Kell proteins. Did they test your husband for both K1 (Kell) and K2 (Cellano) genes, or was it just a blood test? I am so sorry that I can’t be more help. I’m an anthropologist, and maybe a specialist in genetic transmission could help you. Any university would probably have such an expert that you could email.

      Wishing you all success!!!

      1. I am in the same boat as this woman above. I have a 3 year old daughter and my blood test was negative for anti kell antibodies when I had her. But now I am pregnant again and I have the anti kell antibody. My husbands blood work came back negative for the kell antigen. He is 100% the father as well. I was wondering if the woman above ever figured out any answers as to how she contracted the antibody? So far, I have no answers. Thank you!

    2. Hello,

      Did you ever gather any more information on where your antibodies came from? I am currently in the same situation and am totally baffled!
      I have K antibodies, my husband is apparently negative with kk. He is the father of my two boys, and this third pregnancy where these antibodies have shown up for the first time. We also don’t know if the baby is definitely negative if antibodies have shown up in the first place….

      Any suggestions?


      1. Frankly, I am baffled as to how the antibodies got into your system without a blood transfusion or Kk hubby. I would recommend retesting Dad because a false negative is the most likely explanation.

  8. Any ideas on where the pos K people are from?? Me, and ALL of my family, sis, mom, aunts are all K pos, because a blood company wanted us to give blood for money to make diagnostics……. we cannot trace the family tree and were wondering if there was a spot in the world it showed up with more incidence, helping us to know our roots?

    1. People who have that blood have golden blood to me. I can’t have blood transfusions unless they have an exact match as me. I almost died having my son. My baby girl is due in 3 months, even with a c section I can bleed out. I am A- with Kell and Kidd antibodies. It is rare my midwife said to find blood compatible with Kell.

  9. Hi I have 8 children when I was 20 weeks pregnant with baby number 9 they told me I had kell antibodies and during delivery some of my daughters blood must of leaked back into my system to create antibodies , my husband is father to all my children so is it just pure luck we haven’t had any issues till now? My hubby tested positive for kell antigen and is homogenous for kell so all our kids are kell positive , can you please explain how he is homogenous for kell antigen , my pregnancy is now 34 weeks and my tillers have remained stable at 1:28 but today have doubled , baby shows no signs of anaemia via mca scan and no signs of hydrous but they want to deliver in 2 weeks , what does the rise in antibodies mean?

    1. Hi! First, congratulations on your healthy family! First, homozygous Kells (KK) is very, very rare. Did they double check? If he is actually heterozygous (Kk) then yes, you were VERY lucky but not beyond rational expectations. If he is indeed homozygous then I have no idea whatsoever why your other pregnancies didn’t have severe complications. I think it would have to be a deficient immune response by your own body and I have no knowledge about that topic. I’m sure a proper medical doctor would be able to figure it out. I suggest you get one of the boys (other than the first born) and have him tested for Kell antigens. If they are Kell negative, you’ll know the test for your husband was off a bit and that he is Kk, not KK. That means all the children except for the first, your daughter, and #9 will be almost axiomatically Kell negative. They would have no K gene to cause their wives any distress during pregnancy. Yay! Your first born son will need to be tested to know for sure. Your little girl must be Kell+ and #9 must be Kell+ or your body would not be making antigens. Your daughter will not be troubled by Kell+ because her body will not attack the fetus either with or without Kell. If #9 is a boy, every pregnancy after his wife’s first will need to be watched by an OB/Gyn who knows she might be carrying a Kell+ fetus — unless his wife is K+ too, which is rare. PLEASE let me know what the results were if you get a son tested for Kell!! I am very, very glad baby #9 is doing well and I hope he or she has zero problems before, during, or after the birth.

      1. I have to disagree with the midwife Kell antigen negative blood is not rare. Also I think maybe some people are getting g mixed up on this sight. RBcs are packed RBCs they do not contain serum,so with that said RBcs contain antigen. So when you have a transfusion the antigen is being introduced into the body. And what is an antigen—anything capable of causing a reaction. Antibodies are found in serum/plasma. A person can have a specific antibody but at the time of testing it may not be expressing itself and therefore the antibody screen is negative. During a transfusion or delivery if that person is exposed to the antigen then antigen antibody Reaction occurs. If the antibody was not being expressed the next time the patient has an antibody screen that screen will be positive. After a patient has been identified with an antibody they will receive antigen negative blood for that antibidy the rest of their lives. So to recap antigens are on the RBcs and antibody is the plasma. IGG antibodies cross the placenta and therefore if the baby has the antigen then a reaction occurs.

    2. Dear Melanie! I have the same situation as you, during the 6-th pregnancy it appeared I have Kell antigens. The baby is ok, but now I’m really worried about my next pregnancies. Would you kindly give me you contacts, if possible, I’ll ask you some questions. Thanks a lot

  10. I have 7 boys and 1 girl baby number 9 gender not yet known what does being kell positive mean to them and their future offspring please

    1. If the boys are Kell-negative, then they have no worries. If the girl is either Kell positive or negative, it shouldn’t be a problem for her. Kell positive boys can have problems with reproducing, tho.

    1. I am sorry that this got trapped in my comment filter and I just saw it. Sadly I am unsure as to what I could do to help ….

  11. Ok so I am pregnant with baby 4. Baby 3 I had to have a c sec and transfusion. Now I have anti-kell showing up on my blood test. They did a titer all they told me was that it is an 8 ?….

    My husbands waiting to get results to find out if he is kell pos.

    Would my body make the anti-kell show up even if daddy is negative?

    Does anti-kell only show up on blood work when it’s fighting baby….who is kell positive?

    (I’m not sure I even asked these questions correctly)

  12. I became Kell antigen positive after receiving a blood transfusion while giving birth. Will this be a health problem for me later in life. Could I get severe anemic? There’s really not much information out there for this problem that many young moms face today.
    Debbie , New York.

    1. As far as I know (and remember I’m not an MD so if your doctor says otherwise listen to him/her!) you should be fine. Odds are good your body will always make enough red blood cells for you. Hope that helps!!!

    2. Do you mean you have Kell antibody. You are fine except that if you need a blood transfusion in the future you will have to have blood that is antigen negative for Kell. I would encourage you if you are ever hospitalized to be sure that you tell your nurses and doctors that you have an antibody. Antibodies can become unexpressive and the antibody screen will be negative and if your history is not known blood will not be antigen typed.

  13. Hi,
    After giving blood twice I recieved a letter letting me know I was A+ kell. For me this was a big shock, I’ve not had any blood transfusions and have had 2 very healthy boys. I have read a few articles on kell but must have my blonde head on as I can’t get my head round it.

    1. Okay, the GOOD news is that as a K+ woman your pregnancies will never be effected. Your body won’t attack a Kell+ baby because it is the SAME and it won’t attack a Kell- baby because there is no antigen there to set it off. The BAD news is that if either of your sons have your blood type then their partners might (and it is a big if considering genetics) have issues IF the partner is a normal K- and IF the second fetus is K+. You can get the boys tested now and then they can warn their wife/partner if and when pregnancy is a possibility. The best news is that there is a lot they can do nowadays to keep a Kell+ fetus healthy until birth. Remember, YOU are here and you were obviously a Kell+ fetus at one point. Does that help clear things up at all?

    2. This means that you have antibody to Kell which means that if you did not have as blood transfusion that you were exposed to the Kell antigen when delivering your baby. I would think that happened during your last pregnancy since you had no problem with your pregnancy.

      Kell is not a blood type it is antigen found on the red blood cell. Your blood type us A and you are Rh


  14. So, you touched on my question in another comment but I just want to ask in more detail because I’ve been able to find no information on the web…My brother is Kell positive and after his wife had their first child, she developed the antigen. They were pregnant again but lost the baby at 23 weeks due to the problem. 🙁 I understand how it works when the mother is negative and the father is positive. However, I am currently pregnant and am wondering how it could possibly effect my pregnancies. What happens if the mother is Kell positive and the father is Kell negative? Like the punnett square shows, I have a 50% chance of passing it on to baby. I’m assuming if I’m positive and fetus is positive there is no problem. What happens if I don’t pass it on to the fetus and I’m positive but fetus is negative? Thanks for your help!

    1. Hi,
      First, I am sorry for the loss your brother and SIL went through. I hope their next fetus is Kell- or that the Ob/Gyns can do more to help and keep the fetus safe until old enough to be born.
      That being said, a Kell+ woman will not have any problems with pregnancy because of her blood type. If your fetus is Kell+ your body will not attack it because it is the same as your blood type. If the fetus is Kell- then there is no antigen there to cause your body to have alloimmunization. Either way, your babies are safe from issues due to Kell. However, if you have a Kell+ son and his future partner is Kell- then they need to give her a doctor a heads up when/if she gets pregnant.

      1. Thanks for writing back and for explaining how the Kell blood type will effect me. I appreciate your help. Cheers.

      2. If I am Kell +, & My husband is Kell -, babies + or – is currently unknown . . Am I at any risk myself during my pregnancy? I’m 35 weeks and have slight anemia as I did with my 1st baby. I have Orthostatic Hypotension and after my 1st baby girl I ruptured a vein causing me to lose blood when I was already anemic and had a lowish blood count. I did have a transfusion. Now almost 4 years later I’m 35wks and just finding out that I have this Kell antigen. I’ve heard stories of Kell making you severely anemic, and causing women to bleed out even in cases where baby is negative. Am I at risk for anything because of this antigen??

        1. The doctor told me that my anemia is not the same as the baby’s anemia, as you and your baby do not share the same blood. Kell would have also showed up on your initial blood test. I am currently 18 weeks pregnant. I have the antibody and my husband is Kell positive (I formed the antibodies from my first born.). They way they check the baby is through ultrasound and Doppler. I’m already on weekly appointments.

      3. Kell is not a blood type. It is an antigen on the red blood cell. That’s where antigens are located in the red blood cells. Plasma contains antibodies. If you are antigen typed and are Kell positive this means you cannot make a antibodies to Kell. If you are antigen typed and are Kell negative then you have the possibility of formin g antibodies if exposed to the Kell antigen. You cannot have both. This is how immunohematology is performed on the antigen antibody reaction.

        1. If you need more support with Kell… Look up the “ISO moms” group on Facebook. They all have irregular antibodies. About 500 members… So helpful!!y

          1. I can’t find that group. I’d love to find it.

  15. Advice… Other articles have told me that the antigen is very common, while the antibody is not so much. This reads differently. Should my children be told or even be concerned that they are Kell positive f

    1. Do you mean you have Kell antibody. You are fine except that if you need a blood transfusion in the future you will have to have blood that is antigen negative for Kell. I would encourage you if you are ever hospitalized to be sure that you tell your nurses and doctors that you have an antibody. Antibodies can become unexpressive and the antibody screen will be negative and if your history is not known blood will not be antigen typed.

  16. Hello,

    A couple of years ago I had a 13 week ultrasound scan for my pregnancy which showed severe fetal hydrops/cystic hygroma, incompatible with life and therefore the pregnancy had to be terminated. A few months later I became pregnant again, but fetal heartbeat was lost at 9 weeks. Since then, I have not been able to become pregnant again (18 months). As I am spending a fortune on fertility treatments, and have had every other test in the book done, I would like to find out if the Kell and other antigens/antibodies could have caused the problem. However, I am not able to get a clear answer even from my infertility specialist, who said he would have to “look it up” (then promptly forgot/ignored my question). Since I have B negative blood, and my partner O positive I did the direct and indirect Coombs tests after both of my losses to check for RH issues, and they were negative. Does this mean anything for the Kell and other antibodies/antigens? I have been searching all over the net to answer my question but only find general references to “testing” but no explanation of how one goes about testing to see if kell or other similar things are the cause of recurrent pregnancy losses between two partners. I have had every other known test done to determine the issue, so would like to put my mind at ease or proceed with sperm donation which both my partner and I are open to if this is indeed an issue for us. Can you please explain how I would exclude this as our issue, keeping in mind that I am in Eastern Europe and would need to use a common, ‘international’ name for these tests (or maybe go to another country to find them)? Thank you so much for your help, in advance!

    1. I hope the information I sent via Facebook chat will help. My sincere hopes for your future reproductive success.

  17. I’m 15 weeks pregnant and my blood work says I am ‘A positive’, ‘negative’ Coombs indirect but ‘Ccee kell positive’. What I’m not clear on is whether this means I was kell positive from birth and therefore my pregnancy won’t be affected, or kell positive for anti-antigens which I may have picked up from a transfusion during surgery 20 years ago. My doctor doesn’t seem too concerned but says it will need monitoring and the baby may be born with some jaundice. Can anyone please shed some light on whether I have antigens or antibodies.

    1. An indirect climbs test is the same thing as an antibody screen so since your indirect coombs is negative this means you are not expressing any antibodies. I would say that the testing for C e were antigen testing so they were positive which means you cannot make antibodies to those antigens

  18. I have anti Kell antibodies from a blood transfusion I had after the birth of my twins. I am wondering what the risks are for future blood transfutions, and what blood type is compatible. Thank you

    1. First, let me congratulate you on your twins! I am sorry to say that I am not a doctor and cannot help you with future blood type issues, but the good news is you might not need to worry at all: http://www.sciencealert.com/artificial-blood-could-be-used-in-trial-transfusions-by-2016 What I can tell you that as long as any future children are Kell negative it won’t cause any problems in pregnancy. If you plan to have more children, you might want to get your husband to go for a blood test to see if he has Kell+ blood.

  19. i found out about 2 months ago that i have the kell anti-body. 5 yearsz ago i had my 1st son and had to have an emergency c-section which caused me to have blood transfusions to save my life. since then ive had 2 miscarriages til now. i am around 29/30 weeks along in my pregnancy. so far me and my husband who is the father to both of my children, are barely finding out information on this. yesterday we just came back from my 2nd visit to a specialist. the trips r 3 hrs up and 3 hrs back each visit. so far the doctors are thinking that i got this anti-body from the transfusions since we r still waiting on my husbands blood test from last week. so far the baby is looking fine and healthy. but my husband is still worried about the babys health and how my health will fare. but he is also conserned on how his family will twist this around since we dont know much about this anti-body.

    1. I believe, if I understand the timeline, this is your first baby since you contracted the anti-kell antibodies. This many mean that the body will give this little guy/gal a first baby ‘pass’ and you’ll have no worries. If you go for a third or more, there is some risk and make sure you let your OB/Gyn know you have the Kell antibodies. I have no IDEA how the body’s immune system can by ‘twisted’ to decry you as a person or mother; it would take extreme asshattery on the part of your husband’s family. I hope this pregnancy and any future pregnancies go smoothly and without complications!

  20. I am anti-k (little k, used to be called cellano). I went through my last pregnancy (4th child) and had MCA scans, and my baby girl was born healthy and not anemic. My husband has been tested and he is Negative for K (Kell), positive for k (cellano). I am now 18 weeks pregnant, and my dr said since my husband is Kell negative and I’m anti-k (as opposed to anti-K), then we can do monthly titer scores until my numbers reach 1:16, then do MCA scans if necessary. I go to Maternal Fetal Medicine, but I feel like I’m there first anti-k (cellano) patient and they are treating me as if it’s not a Kell antigen. Any advice? Could you respond by email too because I don’t think I could find this feed again if I tried 😉

    1. Actually I checked to be notified by email of follow up comments do we’re good. Thanks!

    2. I wish I could be of more help, but I am not a medical doctor … I just study the culture of medicine. I am sure the doctors are taking all reasonable precautions, tho. OB/Gyns tend to overcompensate on preventatives. Also, if a baby is cellano-negative (which it might very well be and indeed probably is) then the body won’t attack the fetus; your antigens won’t “see” anything there to attack. It will be a normal pregnancy, like your last one. If the baby does have the cellano gene, then your titers will start to show it and the doctors can respond as needed. I hope you and your new baby are very healthy!

  21. I am still confused by this, after I had my first born (daughter) I went to donate blood and was sent a letter that stated there was not a need for my blood type, when I became pregnant with my son I had to go through a amiosenthesis and had a very straining pregnancy. After this I was informed that I could not only not donate blood but could not donate plasma, be a organ donor etc. My ob/gyn also informed me it was not a good idea to have any other pregnancies, and when I had my first back surgery I had to donate blood for myself to be stored. As far as we know I am the only one in my family that has this. How can this be? I have never had a blood transfusion and was A+ all my life until after baby #1. Thank in advance.

    1. Hi Shannon! I wrote you earlier, but my blog didn’t post it. I am not sure why. Perhaps because it wasn’t really helpful. I am not a medical doctor, only a medical anthropologist, and I can but speculate that your first born had a K+ blood type and now you have antigens that will attack any K+ tissue, including another Kell+ fetus. If your body had a really strong response vis-a-vis antigens, then only your body can handle your blood, plasma, ect … Also, a really strong anti-Kell response by your body might indicate a significant risk for your next fetus, in spite of all the medical technology, if it is Kell positive too. I wish I could be more help.

    2. You are still A+ blood type (as am I). Not sure if you are Kell Positive or Anti-K. Probably Anti-K based on what you described. Kell is not a blood type; it is one (among many things) that attaches to some peoples blood cells. Your spouse must be Kell Positive (no harm- just something attached to his blood- and about 10 percent of the US population). Your first child must have been Kell Positive and you were exposed to her blood in pregnancy or labor. Your body recognized the foreign part of the blood (Kell) and built up antibodies to get rid of it… In the same way your body builds up antibodies to get rid of an infection. But these are “irregular antibodies” because they are not fighting against something harmful.
      There is a lot of info online… Just keep researching. I am anti-k (lowercase) so it is kind of like a cousin to Kell. I have had it for two pregnancies ( pregnant with my 5th now, but this issue did not arise until my last pregnancy). My titers have been low… So everything is fine. Thankful to The Lord!

      1. Kyra and Rebecca Ware,
        Thank you for the information it is helpful, I don’t know this helps when I had my first sugrey the hospital sent me this card and it reads:

        ABO GROUP:A, RH TYPE: POSITIVE, ATYPICAL ANTIBOTIES:K (uppercase). The card indicates to keep it and present it to hospital nurses upon hospitalization.

        Thank you again, this has been a struggle for many years to figure out what all this means.


  22. Hi Kyra,

    I have hereditary O RH + Kell blood group past to me from my father which I know is very rare (I’m on the rare blood type register). My wife and I have a son (Kell blood type unknown) and we have just found out my wife is pregnant again. I believe there is a good chance if my son has a Kell blood type that my wife will have K antigens so could you tell me what I should specifically ask the midwife to do regarding this?
    Many thanks in advance for any advice.

    1. I had my first two babies via midwife, so I understand the desire for a low-intervention pregnancy and delivery, but if your wife has the anti-Kell antigens then the pregnancy is officially high risk and will need to go the full biomedical intervention route. The only way to know if she has the anti-Kell antigens is to go to an Ob/Gyn and get the blood tests done to detect them. If she doesn’t have the anti-Kell antigens, then the pregnancy will have no more risks than the average and you can still go to a midwife. However, get more than one test to be sure. The baby could miscarry or die of hemolytic disease of the newborn if your wife unknowingly has the anti-Kell antigens and steps aren’t taken. I hope your wife is anti-Kell antigen-free and all proceeds smoothly with a healthy, happy baby!

    2. Also, I would very much like to know how it is going. Can you post back here and tell me if all is well or not?

  23. I’m female with the normal blood type O+
    The person who proposed to my has the blood type O+ but with kell antigens
    My family scared my and they want me to turn that marriage off, because of the effects of taking “immune globulin intravenous”!!
    Is it that dangerous ?! or they overrated!!
    I say that it’s more look like a woman with a blood type of “-” marrying a man with blood type “+”.
    What do you see as an expert? Are they overrated or is it a big deal?
    Please, I need help, I have to make a decision within a day.
    I can’t take the pressure anymore.

    1. It depends on 1) what kind of health care you can get and 2) luck. Your first pregnancy will not be affected by kell antigens (but could still be one of the 1/3 lost pregnancies; there are lots of things that can go wrong with a normal pregnancy). If you live where you have access to an obstetrician, then there is a lot they can do to make any subsequent kell-effected pregnancies go well. If you only have two or three children, you may never even have a Kell-effected pregnancy, because you might have the good luck that the babies never get your husband’s genes. After all, it is a 50/50 shot, so you have an equal chance of non-Kell genes. If you love him, marry him. If you are more worried than you are in love, then end the relationship. Either way, I wish you the best of luck!!

      1. So how do you know he is Kell antigen positive. Has he been phenotyped. And what about you have you been antigen typed for Kell. Because I don’t really see the concern as you are R h positve

  24. Thanks so much for this info, it explains so much and I understand it so much better. Quick question. So I got pregnant with triplets in November of last year (I also have a 3 year old daughter). I got really sick with a rare blood disease and had to deliver the babies at 18 weeks (worst thing I have ever done). I had to get a blood transfusion after. Well I am 13 weeks pregnant now, and I just was informed by my doctor that I have the anti-kell antigan. My husband quickly went in to get his blood tested and the results came back today that said he was negative. So does that mean that the baby 100% will not have it and I don’t have to worry about a single thing? Thanks for any info!!!

    1. Oh ya, and meant to say that the blood transfusion is how I got the kell.

    2. (Ack! Forgot to post this; my apologies for the delay)

      I am so very, very sorry for the loss of your triplets. The good news is that, as far as I can tell, your husband’s lack of a Kell positive gene means your body will not reject the fetus you are carrying. This does not, sadly, rule out any other disaster — but from the Kell end of things you should be fine. I sincerely hope all goes well!

  25. I am have developed anit kell anit bodies I think for a blood transfusion I had way back in 2003 .my question is I have 7 children all from the same dad
    Oldest is a boy 2nd is a girl the rest all boys .my anit bodies only showed up for my last baby who is now 2 no issues during pregnancy I was watched close. But my husband did not get tested.and if he is postive why would all my other children be fine and why did it just show up 2 years ago .I had the blood transfusion in 2003 and I have had 3 kids in that time all boys.and I had 3 already before that.could my husband still test postive?I am 15 weeks now with my 8 and my level is high at 1.8?

    1. If your babies didn’t inherit the Kell antigen from their dad (and three negatives in a row is not unusual, statistically) before the baby before this one, then you wouldn’t have had an alloimmunization response. However, if the baby before this current pregnancy was Kell positive, now your body has become “allergic” to any Kell positive fetus and will attack your baby. I am really sorry, and I hope medical intervention keeps both you and the baby healthy and the outcome is a joyous one.

      1. Thanks for the answer. And no the baby I had last was kell negative. I know this because the pregnancy and baby were completely normal.i am expecting again and dad has not been tested yet.i was just wondering if there is a chance he could be kell postive after 7 healthy pregnancy and babies .all same dad?

        1. Actually, the FIRST baby you carry with Kell positive blood is safe … it is all other babies after that first Kell positive baby that are at risk. I hope he is not Kell positive, but I have to tell you that yes he could be. It would have been that the other pregnancies had Kell negative babies. (Yes, even five in a row. Random chance works like that. I’m glad all the other pregnancies were healthy!)

          1. I hope I explained why your last healthy baby could have been unknown Kell positive adequately? Please tell me if I didn’t.

          2. Thanks so much for getting back to me.my titer level is 1.8 which is pretty high. Hopefully I am going for an ultersound soon to Check blood flow in brain.as I am 17 weeks now. So as I understand all my other babies were kell negative and if this baby is kell postive my body will give this baby a chance ?

          3. I wish I could tell you with 100% certianty that this baby will be unaffected, but I can’t. I think if your antibodies are that high, then your body has been sensitized. Which means ONE (which one is anyone’s guess and it would take bloodtyping to find out) of your former pregnancies had a Kell positive fetus. Any babies before or after that Kell positive pregnancy that did NOT inherent the Kell antigen were NOT affected. This pregnancy would be the first fetus after a kell positive pregnancy to have the Kell antigen, so it would be your SECOND Kell positive baby. If your next baby has no Kell antigen, then it will be fine. If it DOES inherit the Kell bloodtype then your body will attack it again. It is completely random chance if the baby inherits the Kell gene. I really REALLY hope that modern medical intervention keeps you and your current baby healthy. There is a lot they can do nowadays, so try not to worry yourself sick. Anxiety is hard on the mother and fetus too. BEST WISHES!!!!

          4. Thanks so much for your help.The whole thing is very confusing.

          5. You are very welcome. I wish I could help more. My last post tried to explain the randomness of the Kell reaction, and I hope it made things clearer. Please let me know how you are the baby are doing, and hopefully I will get the delightful news that you had the baby and both of you are healthy and happy.

  26. Hi have three boys after the first I had a blood tranfution went on two baby number two at 37 week they found out that i was kell postive but was not informed about it went on to baby three and found out at 17 wèek blood test that I was had kell postive partaner is negative what dose this mean for future pregnants and for the future of the three boys

  27. I am wondering, can two positive kell people have children together? Or would the kell positive woman still need medical advice/help to conceive and carry to term?

    1. A Kell positive woman will have no reaction to either a Kell negative or Kell positive baby, so they would reproduce without unusual difficulties.

  28. Does pregnancy always have to end in trouble when Kell antigens are involved? I’m the first child of my parents (Kk, my father is KK, my mother is kk). No trouble during that pregnancy. Years later they had another child, also Kk. No trouble there either and apparently no prophylaxis or special treatments given to my mother (I asked).

    1. Your case is certainly different from the norm! For one thing, people who are homozygous (KK) for Kell are rare. Your birth with no complications is usual, in that the first pregnancy is almost always “safe” provided there is no blood transfer. However, your sibling’s birth is unusual because there should have been enough alloimmunization to effect the pregnancy. Either the Kell did not ‘turn on’ and make itself known, or your mom’s body doesn’t have a profound alloimmunizational response.

  29. helloo,
    i have some questions about the kell gene and the risks that it might causes of a baby.
    if the mother has anti kell anti bodies and the father has a kell positive (heterozygous) Kk. the baby has kell positive plus anti kell antibodies? how? and where that came from? will that cause his death?

    1. An indirect climbs test is the same thing as an antibody screen so since your indirect coombs is negative this means you are not expressing any antibodies. I would say that the testing for C e were antigen testing so they were positive which means you cannot make antibodies to those antigens

  30. My wife is pregnant with our fourth child and has had three prior C Sections.

    **Please note, I am not a medical professional, so please forgive any errant use of medical terms in the following**

    My wife’s titers are elevated as she has a number of antigens or antibodies (not sure which is which) in her blood- I believe they were called Kell, E and another… There are three of them. One antigen showed up in a our third pregnancy and now there are three with this fourth pregnancy.

    My blood was tested and I was negative for at least one of the antigens. This seemed to surprise the doctor who offered no explanation as to why in our visit.

    Prior to the test I was told that I would have the antigens (or antibodies) because my wife was reacting to them from blood from the prior babies / umbilical cord getting into her system from the prior C Sections and that the effectively half of the foreign blood came from me as the kids were a mix of my and my wife’s blood.

    My wife has never had a transfusion nor needle stick. Nor is she is a drug user.

    What are some viable reasons these antigens could be in her system?

    Someone put a bug in my ear that it could be infidelity and that one or more of my kids may not be mine biologically…. Please understand, I have thought long and hard about this before posting… whatever the answer, the outcome will not end my marriage. I love my wife and my kids, regardless of their origin. If the only plausible explanation is infidelity, then my goal would be to work on our marriage to stop the practice. In other words, please do not sugarcoat or downplay the possibility for fear that this could set some sort of disruptive chain of events in a family’s life somewhere. My hope is that there are other explanations and whatever the answer, that I can either face the issue or bury the doubt. I sincerely appreciate your consideration.

    1. Okay, the odds that your bloodwork gave a false negative is MUCH higher than the odds of any kids being not yours. Those antigens can doge a test more than people realize. However, a wise doctor would panic and NOT push the issue … just in case. There are still a lot of issues that medical science doesn’t have all the answers for and there are things they are finding out about blood antigens everyday. Moreover if your wife had a C-section then she has had major abdominal surgery and all kinds of transfer can happen. Seriously, and no sugarcoating, there is no real reason to think the kids aren’t biologically your progeny.

  31. I have Read your article a couple times and as a Mother with Kell antibodies, 2 Kell positive girls, your 150 years is extreme. Also, I would say it was quite likely Henry was homozygous for Kell BC if he was Heterozygous there would be a 50/50 chance subsequent children would not be affected. Great strides have been made to help Alloimmunization in pregnancy. Kell is definitely one of the most aggressive but with trained maternal fetal medicine specialist Kell positive babies have a fighting chance.

  32. It appears I’m quite an anomaly, but I guess we knew that.

    My Dad is Kell+. My older sister and my younger half-brother and I all inherited his Kell. Our mothers are both O+ Kell-.

    I did indeed *almost* die in the womb, and the Obstetrician said I probably wouldn’t live very long after birth at the rate things were going. At one point they thought I might be twins, one dead, one alive, because the amnio said my environment was toxic, but my sonogram said my heart was still beating. They said the last three weeks of pregnancy would almost certainly kill me.

    I was born 3 weeks early, with jaundice much more severe than my sister or brother had. And yet, 38 years later, here I am.

    I see there’s some confusion about Kell vs. Anti-Kell. Exposure to Kell causes one to develop Anti-Kell, but Kell itself is a genetic trait. I suppose the confusion is because Kell is an antigen, so Anti-Kell is an anti-antigen?

    I worry, a little, for my half-brother and my sister’s son, that they will have trouble if they want 2 kids, or if they have a partner who has had a prior Kell+ transfusion to react to. It makes me wary of donating blood, because I’ve told them “I have Kell” and the only place that would actually write that down was Stanford. It’s not usually tested for, and yet look at the damage it can do!

    Ahh well.

  33. Hi Kyra –

    I have the very rare Kell Kk polymorphism and had several early miscarriages, at least two of my five adult sons who have been tested are carriers and I have a grandson. In my family of origin I am the eldest of five surviving siblings, four girls and 1 boy, with one additional sibling dying at or before birth between each of us for a total of nine children between my parents.

    Something that drew me to this article is that my last name is Cary, as in Mary Boleyn Cary, mistress of Henry VIII. There was always speculation that her children were actually Henry VIII’s. I wonder if my blood type is actually a connector, although according to the heredity patterns, could the Kk have survived through a father line? I’m pretty sure at least a few of the generations had multiple siblings of both genders.

    There is so little information out there to break this down and I appreciate your work.

    Warm Regards,


    1. First, I am very sorry for your losses. Even when you are mentally prepared, they can still break your heart. It is fairly certain Mary’s son cannot be Henry’s (the dates the king was near here don’t match up). HOWEVER, just being from England (which the name Cary is) means your ancestors had a 9% chance of carrying the gene. You are a rare case, but obviously that does happen. It could carry through the father’s line, since the eldest child could survive having the Kell antigen (Kk) but it is most often via the mother. I hope your two Kell positive sons’ future reproduction will be lucky and their partners are successfully treated by modern OBs if the babies get the K gene!

      1. Hi Kyra –

        Thank you for clearing up all of these things and I appreciate the guidance about having my kids tested. We did not know anything about this until we were tested for genealogy purposes and I only tested two of my sons, so it would behoove us to get everyone tested as well as my grandson. How likely is it that an OB/GYN would have this on their radar if asked? I was thinking maybe my grandson’s mother should get tested just in case.

        I absolutely LOVE your historical research, as a geneology nerd myself it makes me happy.

        Warmest Regards,


        1. If two of your sons are Kell positive, I strongly suggest testing everyone. It could avoid heartbreak in the future. Most OB/Gyns won’t be looking for this problem, because it doesn’t come up all that often. Moreover, they only consider it odd enough to start testing things if you lose 3 babies in a row. (Losing two babies in a row is very common; of every 1000 fertilized eggs 800+ don’t even make it to embryo, so your hormones will frequently “verify” a home pregnancy test based on an implantation that cannot and will not be viable.) If your sons know they are carrying the Kell gene, then their partners can give the docs an early heads-up. Hope all turns out well — Kyra

          1. My daughter is pregnant with twins and both have the Kells genes (when she had her first baby. the placenta broke inside her thus getting blood from the baby who’s dad tested positive) it’s so complicated and I worry so much since the dr. said her case is the first they have seen in that hospital (they live in Calif. ) . The drs will need to do invitro transfusions into the placentas ; however baby A’s is close to her front belly but baby B’s placenta is planted towards her back and that makes it very difficult to perform the transfusions. This is such a scary thing.

  34. I have three children. I’m O- so had Rhogam shots in all of my pregnancies. My first daughter was born without incident. My second child, my son, had mild haemolytic disease of the newborn. I didn’t really understand it at the time but I was told something about other blood groups (m-/n-?). He had some jaundice, and was in an incubator for awhile, but it wasn’t too serious. My third child, another daughter was born with no issues whatsoever. My kids were all blood typed as O+.
    I recently got my 23andMe results back and it is talking about Kell blood groups. It says K-k+ is the most common Kell group in Europeans. My ancestry is all European (mainly British) but my Kell result is K+k+ (and also Kp(a-b+)).
    I’m trying to understand what it means that I’m K+k+. I’m assuming in your terminology its KK, and the typical K-k+ from 23andMe is kk? Would I be safe assuming that my first daughter would be kk and my son kk and my youngest child Kk ?
    I feel like a blood group freak. Not only Rh-, m-n- and KK? How did I not get weeded out of the genetic pool generations ago. Or am I not understanding this at all?

    1. You are not a “freak”. Rare, in that you are less than 10% of the population? Yes. But not a freak. You’re actually Kk, which means you have a Kell+ gene and one without it. KK people are VERY rare. Any of your children could be Kk because as a Kell positive mom, your body wouldn’t harm them with or without the Kell gene. They’ll need to get tested, because your daughters will have no reproductive issues, if your son has the Kk then his reproductive partner’s Ob/Gyn will need to know to keep a close eye on her pregnancies. The babies who had mild jaundice did so most likely because of the “big” antigen groups — A or B.

      1. Ok, yes I had it backwards. Thank you. We are waiting for my son’s results right now. I’m still confused about the Kk vs. KK terminology. There were three options on the 23andMe genetic test: K-k+, K+k-, and K+k+. Mine was K+k+. And the most common for Europeans and Africans was the K-k+. If I’m Kk in your terminology, my son would have a chance of being negative but if I’m KK he would not? Is that correct? But you interpret those results to mean I am Kk so he has a chance?

        1. That’s right. Since you’re Kk your son has a 50% chance of being Kell negative. And even if he DID have the Kell gene, there is lots they could do for his future reproductive partner, and many people with K+ men get lucky and get 3 Kell negative babies in a row. Try not to worry. Your son will be fine 🙂

  35. Hi there, I just got my first blood test result, it says I have anti K(ell) antibodies. I never had any blood transfusions or other pregnancies in my life, could I get this from my parents or husband? This is my first pregnancy after a year of trying (about 7 weeks now) and I am very worried…Do you have any advice for me please? Thank you so much.

    1. Just wanted to add my blood type is A+ , my mum told me I had jaundice and mild anemia when I was born. Does that mean I got this from my parents?

    2. I am sorry, but I am not a doctor, so I may be no help at all. I just have a biology degree and study doctors. Things I know — it is rare, but anti-K antibodies can show up in a first pregnancy, so you aren’t alone. If you are making Kell antibodies (reacting to fetal Kell antigens) then you are Kell negative and had jaundice because your blood type was different from your mum’s. Your husband would be the one who is Kell positive. This is assuming the blood tests are all correct. Tests get false positives or negatives even when done perfectly by the technicians. I am sure your physician will take excellent care of you. I hope your pregnancy is a very, VERY healthy one with no complications. Best wishes — Kyra

      1. Hi Kyra thanks for replying. I phoned the midwife to enquire and was told she made a clerical error, no antibodies in my blood. That episode stressed me out a lot I had to ask my parents about it without telling them Im pregnant… but im glad it was just a mistake.

        1. The #1 explanation for unknown antibodies is a false positive test or clerical error. Glad it all worked out!!!

  36. Good afternoon,

    I have O Positive k-Cellano negative blood. I have had two healthy pregnancies – with my first being a girl and my second being a boy. I will not be having any more children, but am concerned that it may be an issue for them when they have children. Since my blood is so rare, should they be concerned, and is this something they need to have checked? (I have found that most doctors and blood centers don’t check for this because it is so rare.) Thanks in advance for any insight you can provide.

    1. First, I am not a doctor so please don’t hold me up as ‘real’ medical advice! Your daughter should have no issues (related to blood type) and your son’s partner (if he chooses to have kids as adult and falls in love with a reproductively viable woman!) will only have problems IF your son has a Kell positive blood type AND the fetus after the first pregnancy gets the genes for Kell as well. Assume all will be well. They have lots they can do for alloimmunization nowadays, and will be even better in the future I hope, so there is no reason to stress this far away from game day 🙂

  37. Please STOP advising people that if they are kk, and partner is KK or Kk, they will only be able to have one child that is Kk. I work in a blood bank, this is NOT true. Yes, Rh and Kell antibodies are a concern because tend to be relatively immunogenic and cause more severe hemolytic disease of the newborn because they are expressed by a fetus so early and women lose babies. But it is actually MUCH MUCH MORE COMMON to NOT develop antibodies. We have patients getting tranfused liters of K+ blood who don’t ever develop antibodies, much less women from their babies. Also, there are HUNDREDS of antigens a partner could pass to baby that mother doesn’t have– many in the Rh system, Kell system, Kidd system, Duffy, Dombrock, etc.
    In addition, you have a fundamental misunderstanding of McLeod sydrome. It is an X-linked recessive disorder affecting the gene that produces the Kx protein. Think of the protein as the “foundation” the K, k, K3, and many other Kell system antigens “houses sit” on. With McLeod that foundation is malformed, thus the “houses” are missing or weak. It has NOTHING to do if they are KK, or kk, or Kk. Even if genetically otherwise they SHOULD express K or k, they don’t or barely do. Please see Bombay phenotype for a similar situation, these people genetically maybe should be A, or B, but are missing the “foundation” so they don’t express the antigens.

  38. To clarify what you seem to misunderstand, even blood bankers are guilty of calling “K’ the “Kell” antigen, and “k” the “cellano” antigen. But they and many other “Kell” antigens are actually ALL part of the “Kell” system. Everyone has Kell antigens, just different ones, except with Mcleod sydrome they aren’t properly expressed. People with Mcleod syndrome can have major issues, or actually be mostly OK (the person it was discovered in went to Harvard), but the gene for it is really close to the gene for chronic granulomatous disease which is bad business.
    Henry VIII was obese with a years-festering leg wound, gout, maybe a head injury, and on top of that the disposition that comes from being royalty. I do agree severe inbreeding made any number of genetic problems in his babies reasonable, but one can hardly narrow it that far.

Comments are closed.