Navigating the challenges of Bombay phenotype (Oh) and twin pregnancy; a case report and literature review

Abstract Background Bombay phenotype (O h ) is a rare blood group and poses unique challenges during pregnancy, including an adequate supply of blood products in case of postpartum hemorrhage (PPH) and the risk of hemolytic disease of the fetus and newborn (HDFN). Case reports of antenatal care in this cohort are scarce. Herein, we present a case of twin pregnancy in an O h woman and outline her multidisciplinary management. We summarize the literature to better inform decision‐making and patient blood management in the antenatal care of O h women. Case description A 22‐year‐old G1P0 presented at 15 weeks gestation with dichorionic diamniotic twins and known O h phenotype. Hematinics were optimized to minimize anemia. Anti‐H titers were tracked and were 1:256 at both 28 and 36 weeks gestation. Regular middle cerebral artery dopplers were performed to assess for fetal anemia. There was constant communication with obstetrics and anesthetics teams. Both autologous frozen and directly donated fresh red cells were available as part of a clear, detailed transfusion plan. Transfusion was not required and neither child was affected by HDFN. The neonates were group O, DAT negative, and group A, DAT positive. Maternal anti‐A was detected in the neonatal eluate. Conclusion To our knowledge, this is only the second report of twin pregnancy in an O h female and the first time a detailed transfusion plan has been published. Through employing patient blood management strategies, engaging a collaborative multidisciplinary approach, and establishing a clear delivery plan, the antenatal challenges of Bombay phenotype are surmountable.