An Rh-negative multigravida delivers an Rh-positive infant. Her indirect Coombs test performed at 28 weeks was positive with anti-D identified in her serum. The Kleihauer-Betke test after delivery shows 0.05% fetal cells. What is the correct action regarding postpartum anti-D immunoglobulin?

• A Give 300 mcg anti-D within 72 hours of delivery
• B Give 300 mcg anti-D and repeat the Kleihauer-Betke test in 72 hours
• C Give anti-D only if the neonatal direct Coombs test is negative
• D Withhold anti-D immunoglobulin ✓

Explanation

Anti-C immunoglobulin works by clearing fetal C-positive cells before the maternal immune system responds, so it benefits only unsensitized women. This mother already has circulating immune anti-C detected on indirect Coombs testing, meaning active sensitization occurred in a previous pregnancy. Administering anti-C cannot reverse existing antibody production and serves no purpose. The newborn will be monitored for hemolytic disease based on maternal titers and neonatal hemolysis parameters. Immunoprophylaxis is directed at preventing sensitization, never at treating established alloimmunization.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.