DEAR DR. MONA: My daughter is pregnant and her doctor told her that will need to get a rhogam shot at 28 weeks and then after she delivers. We don’t feel that she needs it and are considering declining. What do you think about this? — Doreen
DEAR DOREEN: The Rh sensitization process is dangerous and we have not seen much of this problem for 30 years or more because of the understanding of this disease and how to handle it. Let’s talk about it and then you will know why the treatment is needed.
Blood cells in our body have proteins on the surface where we can identify blood types (such as the A, B, AB and O). In addition, there is another antigen on the blood cell surface known as the Rhesus (Rh) factor.
If the factor is found to be present on the blood cells it is called RH positive, which is the case in 85 percent of the population. Fifteen percent of the population lack the RH factor and are called RH negative.
The inheritance pattern of this gene is usually recessive, which means both genes have to be negative (i.e. mother and father have to be negative for a baby to be RH negative). If the father is positive and the mother is negative, the baby will be positive which is most common.
In a case where the mother is negative and the baby is positive, if there is a blood exchange between the mother and the baby, the mothers’ body considers the baby’s blood as a foreign body and starts to form antibodies to attach to the baby’s blood cells. This blood exchange could happen at any time during the pregnancy — if there is bleeding — or at delivery. If this occurs, the mother is “RH sensitized.”
The first baby in such a patient is usually not affected; however, any future babies are always at risk.
The mother’s body forms antibodies and the next babies will be attacked and will suffer from anemia because the antibodies will attack their blood cells and break them down. The fetal anemia could be prevented by monitoring the baby and possibly blood transfusion during the pregnancy through the umbilical cord.
In addition, early delivery might be needed to save the baby. This is becoming a rare need because of the wide spread immunization with Rhogam or Rhophylac.
Rh negative mothers can avoid this problem by getting a rhogam shot. Rhogam is an immune globulin (RH D). This protein binds to the surface of the mother’s blood cells and does not allow the cells to recognize the baby’s blood cells and form antibodies to attack the baby during the highest chance of maternal fetal blood exposure (28 weeks and the delivery time). Getting this injection is safe process and prevents the development of this disease.
Any bleeding during the pregnancy of an Rh negative mother should be reported to the physician because there might be a need to treat with rhogam. Pregnant women who experience a spontaneous miscarriage or ectopic (tubal) pregnancy should also be treated with rhogam to prevent future sensitization.
As you can see, this is an avoidable risk and it is imperative to understand the impact of refusing treatment. It is estimated that use of the rhogam avoids 10,000 infant deaths per year.
It is an unfortunate trend these days to question immunizations of any kind, but if you and your daughter still think you want to refuse the treatment, you should understand clearly the effect on the future pregnancies.
Please discuss with your doctor and see what she/he can offer you to read or educate you.
Dr. Mona Alqulali is a board certified OB-GYN.