What is the recommended counseling for a 29-week pregnant Rh (Rhesus) negative mother, whose babies' father is Rh positive, and who did not receive RhoGAM (Rho(D) immune globulin) in her last pregnancy due to concerns about its effects on her previous baby?

From the Guidelines

I strongly recommend that this mother receive RhoGAM (Rh immunoglobulin) during her current pregnancy to prevent sensitization to the Rh factor, despite her concerns about its safety based on her previous experience. The risk of alloimmunization is significant, especially considering that fetal red cells can be found in the maternal circulation as early as the first trimester, with estimates suggesting that nearly 90% of cases of fetomaternal hemorrhage and alloimmunization occur at delivery, but can also happen during pregnancy due to various obstetric procedures or events such as ruptured membranes or vaginal bleeding 1.

Given her Rh-negative status and the father's Rh-positive status, the risk of the baby being Rh-positive is high, which increases the risk of sensitization if she does not receive RhoGAM. She should receive 300 mcg of RhoGAM at 28 weeks gestation and another dose within 72 hours after delivery if the baby is confirmed Rh positive, as this has been shown to significantly reduce the risk of alloimmunization, with studies demonstrating a 90% decrease in alloimmunization in treated patients compared to untreated patients when tested at 6 months postpartum 1.

It's crucial to address her misconception that RhoGAM made her previous baby sick, as RhoGAM is a preventive treatment given to the mother and does not cross the placenta to affect the fetus. Without RhoGAM, she risks becoming sensitized to the Rh factor, which could cause hemolytic disease of the fetus and newborn in this or future pregnancies, leading to severe anemia, jaundice, brain damage, or even fetal death. Since she missed RhoGAM in her previous pregnancy, she should be tested for Rh antibodies immediately to determine if sensitization has already occurred. If she has not developed antibodies yet, RhoGAM can still provide protection. The injection is administered intramuscularly, typically in the deltoid or gluteal muscle, and side effects are generally mild and limited to the mother, such as soreness at the injection site.

Key points to consider in counseling her include:

• The importance of preventing sensitization to the Rh factor to avoid complications in current and future pregnancies.
• The safety and efficacy of RhoGAM in preventing alloimmunization, as supported by observational studies and the significant reduction in fetal mortality from Rh hemolytic disease following the introduction of postpartum and antenatal RhoGAM prophylaxis programs 1.
• The need for immediate testing for Rh antibodies to assess her current sensitization status.
• The administration schedule and potential side effects of RhoGAM.

From the FDA Drug Label

RhoGAM is indicated for administration to Rh-negative women not previously sensitized to the Rho(D) factor, unless the father or baby are conclusively Rh-negative, in case of: Antepartum prophylaxis at 26 to 28 weeks gestation RhoGAM(300 µg)(1500 IU)Postpartum (if the newborn is Rh-positive)Administer within 72 hours of delivery. If antepartum prophylaxis is indicated, it is essential that the mother receive a postpartum dose if the infant is Rh-positive.

The patient is at 29 weeks of gestation and has an Rh-negative blood type, while the father of the baby is Rh-positive.

• The patient should receive RhoGAM for antepartum prophylaxis since she is at 29 weeks gestation, which is close to the recommended 26-28 weeks.
• It is essential to administer RhoGAM to the mother to prevent Rh immunization.
• A postpartum dose of RhoGAM is also recommended if the infant is Rh-positive. 2

From the Research

Counseling the Mother

• The mother is 29 weeks pregnant, RH negative, and the father of the babies is RH positive.
• She did not receive RhIG in her last pregnancy due to concerns that it made her baby sick in a previous pregnancy.
• It is essential to counsel her on the importance of RhIG in preventing Rh alloimmunization and hemolytic disease of the newborn (HDN) 3, 4, 5, 6.
• The risk of HDN can be minimized with proper administration of RhIG, and the mother should be informed about the benefits and risks of the treatment 7, 3, 4, 5.

Administration of RhIG

• According to the guidelines, RhIG should be administered to RH-negative women at 28 weeks' gestation, and a second dose may be given at 34 weeks if the fetal blood type is unknown or RH positive 3, 4.
• The mother should be informed that RhIG is generally safe and effective in preventing Rh alloimmunization, but rare cases of HDN due to RhIG have been reported 7.
• It is crucial to discuss the mother's concerns and address any misconceptions she may have about RhIG and its effects on her baby 3, 5.

Importance of RhIG Prophylaxis

• RhIG prophylaxis is approximately 99% effective in preventing maternal sensitization to Rh(D) 6.
• The mother should be informed that failure to receive RhIG prophylaxis can result in significant morbidity and mortality in children due to HDN 6.
• It is essential to emphasize the importance of complying with the recommended RhIG prophylaxis schedule to minimize the risk of HDN 3, 4, 5, 6.