Perinatal Outcomes in Pregnancies Complicated by Maternal Thrombocytopenia: A Retrospective Cohort Study.

Background/Objectives: Maternal thrombocytopenia, affecting approximately 10% of pregnancies, may be physiological (e.g., gestational thrombocytopenia) or pathological (e.g., immune thrombocytopenic purpura, aplastic anemia, preeclampsia, systemic lupus erythematosus). While gestational thrombocytopenia is typically benign, its severity and etiology may impact maternal and neonatal outcomes. This study examined the association between severe and moderate thrombocytopenia during pregnancy and perinatal outcomes, focusing on maternal hemorrhage and neonatal thrombocytopenia. Methods: A retrospective analysis was conducted of 182 pregnant women with thrombocytopenia who delivered at Incheon St. Mary's Hospital and Seoul St. Mary's Hospital between 2009 and 2019. Participants were classified into two groups: severe thrombocytopenia (platelet count <50 × 109/L) and moderate thrombocytopenia (50-150 × 109/L). Maternal hemorrhagic outcomes, transfusion needs, and neonatal platelet counts were evaluated. Statistical analyses were performed using univariate methods. Results: Severe thrombocytopenia was associated with greater blood loss during delivery, increased transfusion requirements, and elevated neonatal thrombocytopenia rates. Moderate to severe thrombocytopenia was more frequently identified in neonates delivered by mothers with immune thrombocytopenic purpura than in those delivered by mothers with gestational thrombocytopenia. Conclusions: Both the severity and etiology of maternal thrombocytopenia significantly affect the risk of maternal hemorrhage and neonatal thrombocytopenia. Careful prenatal assessment is essential to optimize management and reduce complications.