A Rh-negative mother delivers a Rh-positive infant. What is the essential immunoprophylaxis?

• A. Rho(D) immune globulin (RhoGAM) within 72 hours postpartum; also ensure 28-week prophylaxis if not given.
• B. No immunoprophylaxis is required.
• C. Vaccinate the mother with Rh immune serum during pregnancy.
• D. Administer Rh prophylaxis only if the newborn shows signs of hemolysis.

Answer: (A)

The key idea is preventing maternal sensitization to the Rh(D) antigen. When an Rh-negative mother carries an Rh-positive baby, fetal red cells can enter the maternal bloodstream. Giving Rh immune globulin (RhoGAM) provides anti-D antibodies that bind those fetal cells in maternal circulation, so the mother's immune system doesn’t recognize them as foreign and doesn’t form its own anti-D antibodies. That protection is what reduces the risk of hemolytic disease in future pregnancies.

Timing matters: administer Rh immune globulin around 28 weeks of gestation as routine prophylaxis, and give another dose within 72 hours after delivery if the newborn is Rh-positive. This two‑time approach covers both the late-pregnancy and postpartum periods. It’s preventive, not reactive to signs of hemolysis, and there’s no vaccine for Rh—Rh immune globulin is used to prevent sensitization, not treat it after it has occurred.