A pregnant woman at 20 weeks develops a febrile illness with a slapped-cheek rash. Fetal ultrasound at 28 weeks shows scalp skin edema, ascites, and pericardial effusion with a middle cerebral artery peak systolic velocity above 1.5 multiples of the median. Which intrauterine intervention addresses the underlying mechanism?

• A Maternal immunoglobulin infusion to suppress fetal viremia
• B Early delivery by cesarean section at 30 weeks
• C Intrauterine transfusion of packed red cells to correct fetal anemia ✓
• D Fetal blood sampling followed by intrauterine platelet transfusion

Explanation

Parvovirus C19 infects erythroid precursors via the P antigen, causing profound fetal anemia, high-output cardiac failure, and immune-style hydrops. Management of significant hydrops is intrauterine packed red cell transfusion, often guided by the elevated middle cerebral artery Doppler velocity, with spontaneous resolution possible in milder cases. Maternal immunoglobulin has no established fetal benefit, platelet transfusion does not address the mechanism, and delivery does not treat the anemia.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.