What is the recommended time frame to administer Rh immune globulin after birth for an Rh-negative mother with an Rh-positive baby?

What is the recommended time frame to administer Rh immune globulin after birth for an Rh-negative mother with an Rh-positive baby?

• A. Within 24 hours after birth
• B. Within 72 hours after birth
• C. At 2 weeks postpartum
• D. During pregnancy only

Answer: (B)

Rh immune globulin after birth prevents the Rh-negative mother from becoming sensitized to Rh-positive fetal red cells that may enter her circulation during delivery. If sensitization occurs, the mother can develop anti-D antibodies that threaten future pregnancies. The best time to give this prophylaxis postpartum is within 72 hours after delivery because the fetal red cells are present in the maternal circulation soon after birth, and treating within this window neutralizes those cells before the maternal immune system can mount a response. Giving it earlier within 24 hours is not incorrect, but the critical practical window is up to 72 hours. Waiting longer, such as two weeks postpartum, increases the risk of sensitization, and administering only during pregnancy would miss fetal cells that enter the maternal system at delivery.

Rh immune globulin after birth prevents the Rh-negative mother from becoming sensitized to Rh-positive fetal red cells that may enter her circulation during delivery. If sensitization occurs, the mother can develop anti-D antibodies that threaten future pregnancies. The best time to give this prophylaxis postpartum is within 72 hours after delivery because the fetal red cells are present in the maternal circulation soon after birth, and treating within this window neutralizes those cells before the maternal immune system can mount a response. Giving it earlier within 24 hours is not incorrect, but the critical practical window is up to 72 hours. Waiting longer, such as two weeks postpartum, increases the risk of sensitization, and administering only during pregnancy would miss fetal cells that enter the maternal system at delivery.