An Rh-negative unsensitized woman at 31 weeks presents with antepartum hemorrhage from suspected placental abruption. Which investigation is indicated to quantify fetomaternal hemorrhage before administering anti-D immunoglobulin?

• A Kleihauer-Betke test on neonatal cord blood
• B Rosette test on cord blood
• C Indirect Coombs test on maternal serum
• D Kleihauer-Betke acid elution test on maternal blood ✓

Explanation

The Kleihauer-Betke acid elution test identifies fetal cells containing HbF in the maternal circulation, allowing calculation of the volume of fetomaternal hemorrhage and the dose of anti-A required. It is performed on maternal peripheral blood. The indirect Coombs detects maternal anti-A antibodies but does not quantify fetal bleed size, and testing neonatal blood cannot measure how many fetal cells entered the mother.

Reference: Dutta's Textbook of Obstetrics, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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