Massive fetomaternal hemorrhage and successful prevention of maternal
RhD
alloimmunization: A case report
Sajjad Hassan, Angela Essa, Lauren Orr, Corina N. Schoen, Chester Andrzejewski Abstract
Background
Massive fetomaternal hemorrhage can lead to significant fetal morbidity or mortality. RhD negative patients require appropriate treatment to prevent alloimmunization in subsequent pregnancies. Few cases with follow‐up into future pregnancies have been reported.
Case Report and Results
30‐year‐old gravida 3 para 1 presented at 40 weeks and 2 days gestation for late term evaluation. Ultrasonography identified an intrauterine fetal demise. The patient was O RhD negative and had previously received Rh immunoglobin (RhIG) at 26 weeks of gestation. The patient was induced and delivered a 3,450 gram stillborn fetus. Kleihauer‐Betke testing performed and revealed massive fetomaternal hemorrhage with a result of 5.4–6.0%. The calculated fetomaternal hemorrhage was estimated to be 281.6 mL (approaching the total estimated fetal blood volume of 293 mL). The patient received 3 vials of intramuscular RhIG (300 μg/vial), 2 vials of intravenous RhIG (1,000 μg/vial), and 1 vial of intravenous RhIG (300 μg/vial) for a total RhIG dose of 3,200 μg, over a 3‐day period, with no adverse clinical sequelae. Serological investigations for anti‐D antibodies remained positive until 6 months and were inconclusive at 8 months postpartum. At 10 months postpartum, she was 9 weeks pregnant and no anti‐D antibodies were detected. With this subsequent pregnancy, she was treated with routine RhIG and delivered a healthy RhD positive neonate.
Conclusion
Adequate dosing of RhIG can be achieved to prevent alloimmunization, even in massive fetomaternal hemorrhages. After large doses of RhIG, anti‐D antibodies may persist for several months and do not necessarily indicate maternal alloimmunization.