How To Determine and Manage Rh Incompatibility

Rh incompatibility only applies if a mother has Rh- blood and the baby’s father has Rh+ blood. In that situation, It’s important to know the facts and for the mother to get proper treatment.

Dr. Greene’s Answer:

Corina, you are right to be concerned about your situation.  Let me take a step back and explain more. 

Every snowflake is different and each person is even more so! Each cell in our bloodstream carries our own genetic signature. A constellation of proteins on the surfaces of the cells allows our bodies to distinguish between our own blood and someone else’s. These protein patterns are roughly divided into groups that we call blood types.

Not only are blood types different but some types of blood are incompatible with some others. The white blood cells in some types will perceive other types as enemies, attacking and destroying the other blood. This problem is most significant in people with Rh incompatibility.

Why Rh- Blood Is Important to Understand

People are called Rh-negative if they do not have the rhesus (Rh) protein on the surfaces of their blood cells. If Rh-positive blood cells get into the bloodstream of someone who is Rh-negative, the body of that Rh-negative person will see this as an enemy invasion.

Unprepared, the Rh-negative person will begin to make antibodies (what you call anticorps) against the foreign Rh protein. This first exposure is often not even noticed, but your body is still making antibodies. The next time an exposure occurs, the body is primed to seek and destroy all Rh-positive blood cells. All-out war can occur inside an Rh-negative person’s body. This can lead to serious medical complications.

Hydrops Fetalis

A terrible condition called hydrops fetalis can be the result of that war. Rh incompatibility produces a wide variety of outcomes. Sometimes only mild anemia and perhaps a little jaundice are the only signs there has been a conflict.

But sometimes the results are much more serious and require invasive treatments. The first pregnancy is rarely a problem because blood is often not exchanged until the time of birth. But with each subsequent pregnancy, the risk for hydrops increases.

Hydropic Babies

Hydropic babies are bloated, swollen, and pale. Enlarged hearts, livers, and spleens are unable to perform their vital duties. The swollen lungs can make breathing impossible. Many hydropic babies are stillborn. Many die shortly after birth.

In 1963 an event occurred that began to change the story. Jorg Schneider, who was at the Freiburg University Hospital in Germany at the time, became the very first investigator to give pregnant, Rh-negative women a shot of Rh antibodies to prevent their immune systems from mounting their own response to Rh-positive cells.

The exact date of this achievement was August 9, 1963. One year later, Schneider reported that nine women, following delivery of Rh-positive children, did not develop Rh antibodies during subsequent pregnancies with Rh-positive fetuses.

Preventing Hydrops Fetalis

Since then, prevention programs have been implemented in many countries around the world. In Great Britain, the number of deaths from hydrops has dropped 96% in the years since the prevention program began in 1970. This experience is typical.

By giving anti-D globulin (RhoGAM) to Rh-negative moms during and shortly after each pregnancy (including after miscarriages and abortions), more than 99% of mothers will not develop anti-Rh antibodies. Unfortunately, a small number still do, and the consequences are can be serious.

Being Rh-negative is a recessive trait. This means that a person needs to have two negative genes to be Rh-negative and will always give one negative gene to any offspring. Being Rh-positive is a dominant trait. This means that an Rh-positive person can have two positive genes or one positive and one negative gene. If your husband has a positive and a negative gene, then about half of your offspring will be Rh-negative (and there should be no trouble carrying an Rh-negative child). But about half of your offspring will be Rh-positive (and if your mate has two positive genes, all of your offspring will be Rh-positive). This is a very risky proposition.

Healthy, Rh-positive children have been born to women with high titers, especially if they have had the RhoGAM and the titers are still high. Having a blood type B mom and a blood type A baby is also somewhat protective. But the pregnancy should be monitored closely and carefully managed by an expert in this area, even before conception. For a successful outcome, the baby may need blood transfusions every 3 to 5 weeks even before being born. Delivery is induced as early as is safe.

Success Rates

Even if birth is successful, the infant should be cared for at a well-prepared medical center. The baby may need aggressive treatment for anemia, immunodeficiency, and jaundice shortly after birth.

When I was born, hydrops fetalis was an almost hopeless situation. Today, preventing Rh-negative moms from being sensitized is extremely (but not completely) successful at preventing hydrops wherever the guidelines are followed. All of this with a couple of simple, but ingenious shots! However, once a mom has become sensitized, things are not so simple. Future pregnancies may turn out fine, but sometimes massive, complex, medical interventions are necessary — and even with these, a good outcome may not be possible.

So, Corina, you have a very difficult decision to make. I’m afraid I cannot tell you whether you can safely have another child or not. But I do encourage you to weigh the odds, speak with your doctors, and to appreciate the beautiful, healthy child you already have.

Resources and References

ACOG Committee on Practice Bulletins — Obstetrics. Practice Bulletin No. 181: Prevention of Rh D alloimmunization. Obstet Gynecol. 2017;130(2):e57-e70.

Pegoraro V. Hemolytic disease of the fetus and newborn due to Rh(D) incompatibility: A preventable disease that still produces significant morbidity and mortality in children. PLoS One. 2020;15(7):e0235807.

Photo credit: Digital Skillet

Dr. Greene is a practicing physician, author, national and international TEDx speaker, and global health advocate. He is a graduate of Princeton University and University of California San Francisco.

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  1. Naamala.Ephrance

    iam 0+ and my boyfriend is also 0+…Are there possible compatibility issues that we might face when we decide to have children?

    Added:
    • Naamala,

      Thanks for writing in.

      There are not blood type compatibility issue for a mother with O+ blood and a father with O+ blood.

      Best, @MsGreene
      Note: I am the co-founder of DrGreene.com, but I am not Dr. Greene and I am not a doctor. Please keep that in mind when reading my comments and replies.

      Added:
  2. gaby

    I am A- my husband is O+ our son is A- my husband asked my doctor is this possible the doctor replied that it’s like having black coffee and mixing it with coffee with cream and end up with black coffee. What are the chances of this happening, i have always been faithful but my husband does not believe he is the father… HELP please and thank you for your time

    Added:
  3. Rahul

    My wife is O+ and I am A+. We had an IVF procedure with a donor egg. The donor is B-

    I have spherocytosis(passed from my mother) and underwent an exchange transfusion at birth and a splenectomy later on. I have been very healthy after the splenectomy.

    We are 4 months pregnant with twin girls. My questions are:

    Is there a risk of Rh incompatibility between my wife and her twin girl babies?

    Is there a risk of blood group incompatibility between my wife and her twin girl babies?

    For the above two if Yes, how do we manage this now prophylactically and after birth?

    Is there a heightened risk of having used the egg of a donor who is B negative given my spherocytosis? What should we be doing about this?

    Added:
  4. leah

    My mom is rh – and im a-. What blood type would my father be?

    Added:
  5. Janice

    I’m Rh factor o- and my mother is o positive. What would my fathers blood Type be?

    Added:
    • Janice,

      Your father could be either Rh+ or Rh-.

      Let me know if you’d like an explanation.

      Best,
      @MsGreene

      Added:
    • Funke Ayeni

      i am is 0- and my husband A+..
      what can we do for the pregnancy

      Added:
      • Funke,

        Congratulations on your pregnancy. What an exciting, and for you, possibly a scary time.

        The most important thing you can do is let your doctor know your blood types and make sure she or he is on top of the situation. Per Dr. Greene, “By giving anti-D globulin (RhoGAM) to Rh-negative moms during and shortly after each pregnancy (including after miscarriages and abortions), 99% of mothers will not develop anti-Rh antibodies.”

        Note, there isn’t typically any problem with the first pregnancy, it’s only subsequent pregnancies that have an issue. BUT you need to get the anit-D globulin shots with each pregnancy.

        I hope that helps.
        Best, @MsGreene
        Note: I am the co-founder of DrGreene.com, but I am not Dr. Greene and I am not a doctor. Please keep that in mind when reading my comments and replies.

        Added:
  6. Pamela

    I am a female twin with o blood my twin brother is b-…I don’t know if I am positive or negative will know tomorrow…are we from the Rh bloodline

    Added:
  7. Jen Lisa

    Is there any way possible that both my parents are O+ and I am A+? That is the situation here and I look like both my mother & my father.

    Added:
    • Jen Lisa,

      Our latest science, which we may find is not accurate, would say this is not possible. Often results like this are because one of the three tests is in error. I know there are families who swear the mother and father are the biological parents of a child that is “impossible”. If repeat testing shows the same outcome, DNA tests can provide more information, but even DNA testing is not perfect.

      I hope that is helpful.
      @MsGreene

      Added:
      • King

        Doc I am.O+ and wife is AB. What are my children

        Added:
        • Hi King,

          Thanks for writing in.

          If one parent is O+ and the other is AB+, each of their children can be A+, A-, B+ or B-.

          I hope that’s helpful.

          Best, @MsGreene
          Note: I am the co-founder of DrGreene.com, but I am not Dr. Greene and I am not a doctor. Please keep that in mind when reading my comments and replies.

          Added:
  8. Dina lotjem

    Hi! We are newly married couple. I am A- and my husband O+. Is there a problem to our future child?? Need help. Thank you.

    Added:
    • Dina,

      Congratulations on your marriage. It’s great that you’re asking questions about Rh- incompatibility now.

      As Dr. Greene outlines in this article:

      “Unprepared, the Rh-negative person will begin to make antibodies (what you call anticorps) against the foreign Rh protein. This first exposure is often not even noticed. The next time an exposure occurs, though, the body is primed to seek and destroy all Rh-positive blood cells. All-out war can occur inside an Rh-negative person’s body.

      A terrible condition called hydrops fetalis can be the result of that war.

      … The first pregnancy is rarely a problem because blood is often not exchanged until the time of birth. But with each subsequent pregnancy, the risk for hydrops increases.

      … In 1963 an event occurred that began to change the story. Jorg Schneider, who was at the Freiburg University Hospital in Germany at the time, became the very first investigator to give pregnant, Rh-negative women a shot of Rh antibodies to prevent their immune systems from mounting their own response to Rh-positive cells.

      … Since then, prevention programs have been implemented in many countries around the world. In Great Britain, the number of deaths from hydrops has dropped 96% in the years since the prevention program began in 19701. This experience is typical.

      By giving anti-D globulin (RhoGAM) to Rh-negative moms during and shortly after each pregnancy (including after miscarriages and abortions), 99% of mothers will not develop anti-Rh antibodies.

      Please bring your status to your physician’s attention so you can receive the treatment you need when you need it.

      Best,
      @MsGreene

      Added:
  9. marj

    Im 27 now and having PCO.
    My husband is 34 now and AB- and mine B+ is our blood type compatible?is there a chance to conceive?is there any problem to our future child?need help. Thanks.

    Added:
    • Marj,

      Rh incompatibility is only an issue if the mother is Rh- and the father is Rh+. From your report, this is not your situation.

      I hope that’s helpful.
      @MsGreene

      Added:
  10. Renae Corbin

    If I am O- an my child is O- what would the father be

    Added:
  11. Sharon White

    Hi there I was wondering my husband is O- & I am A+. I thought my daughter was A+ . But she was told by the blood bank she is O+. How can that be? Please explain. Thank you, SMW

    Added:
    • Hi Sharon,

      The ABO and Rh systems of classification are different. Parents do pass down both the blood type and the Rh type, but they are independent, so it’s not unusual for a child to be different from either parent. In the example you gave, here are the odds:
      — 75% chance of being Blood Group A
      — 25% chance of being Blood Group O
      — 75% chance of being Rh+
      — 25% chance of being Rh-

      This means the child of one parent who is O- and one who is A+ could be:
      — A+
      — O+
      — A-
      — O-

      Hope this helps.
      @MsGreene
      Co-founder and Executive Producer, DrGreene.com

      Added:
  12. Angel Tompkins

    If the man I am planning to marry is O- and I am O+ what is the possible outcome of our children’s blood type, I have read the questions above and I am confused. What does Rh- and Rh+ stand for in medical language. I do want children who are healthy and I want more than one and I care for my own health and I live in a preventable way and do not look to cause myself or my future family problems in any way. The world around me has plenty.

    Added:
    • Hi Angel,

      The issue with blood type incompatibility come when the mother is Rh-. There is no issue if the father is Rh-.

      Two people with type O blood will have children who are type O. This is the most common blood type.

      Your blood types should not cause any issues in having multiple children.

      Hope that helps,
      @MsGreene
      Co-founder and Executive Producer, DrGreene.com

      Added:
  13. Johnn

    Hay my mother is O+and the man she keeps telling me is my father is B+but yet I’m A-I’m confused about it all is there any possibility that he is my father because I’m A- and I try explaining it to my mother because I don’t believe that there is a chance at all

    Added:
    • Hi John,

      One of your blood types may not be what you think it is, but the scenario you’ve outlined is not considered possible. Here’s why …

      Each person has two alleles that make up their blood type. Here is how that looks:

      — Type A = A & O or A & A
      — Type B = B & O or B & B
      — Type O = O & O
      — Type AB = A & B

      Each parent gives one allele to their child. In this example:
      — Type O can only give an O
      — Type B can give an B or an O

      The child can be:
      — Type O = O from one parent and O from the other parent
      — Type B = B from one parent and O from the other parent

      Before you draw any conclusions, though, it’s wise to have everyone retested. It’s possible that the original tests had an error, they were reported incorrectly, or people’s memory of their own blood type is in error.

      I hope that’s helpful,
      @MsGreene
      Co-founder & Executive Producer, DrGreene.com

      Added:
  14. Dave

    Doc. How is it possible for parents that are both O negative to have a baby that is O positive.

    Added:
    • That is not considered a possible outcome.

      As I’ve said here many times — 1) our scientific knowledge is always growing 2) Retest before jumping to any conclusions.

      Best,
      @MsGreene

      Added:
  15. Sanida, Bosnia and Herzegowina

    Dr. Greene, my Blood Group is B, Rh negative; my husband’s Blood Group is A, Rh positive. We already have a son and daughter with Blood Group B positive. And in addition to regular income Rogham, after the second birth I became Rh sensitive , and I only found out in the 16th week of pregnancy third . Antibody titer in 16th week was 1 : 256 , in the 18th 1 : 128. My doctor says the baby is healthy and everything is fine , but to avoid any complications , it is better to do an abortion. Please, help me..What can I do?

    Added:
  16. Yetty

    Dear Dr. Greene, I need your advice please. I am O+ while my hubby is B-. I have a son who had jaundice shortly after birth. My doctor didn’t mention anything about the cause and the need for injection to prevent my body building up antibodies. However, I recently stumbled on Rh incompatibility and I’m a little confused as we are planning on making another baby. Could you please advise me on what to do? Thanks for your time.

    Added:
    • Muhammed

      Yetty, you will not need any injection as your blood type and is not B rhesus negative (B -). This particular injection is for rhesus negative mothers

      Added:
  17. Brittany Crowley

    So I have a very important question my mother is -AB blood and my father is O- my mother seems to believe I have O+ but as I recall she said my blood type is the same as my dads

    Added:

Comments are closed.