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.

Question

Dr. Greene, my Blood Group is B, Rh negative; my husband's Blood Group is A, Rh positive. We already have a child, but we want to have another one. My last blood analysis shows that my anticorps Anti-Rh were very high. The question is: Can I have another child?
Corina Oteanu - Bucharest, Romania

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.

Last medical review on: August 13, 2021
About the Author
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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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31 Comments
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Recent Comments

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.

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

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.

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.

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

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.

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.

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

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.

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

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?

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

Janice,

Your father could be either Rh+ or Rh-.

Let me know if you’d like an explanation.

Best,
@MsGreene