The association of mild thrombocytopenia that impact on increasing risk of postpartum hemorrhage

Abstract

Postpartum hemorrhage (PPH) is one of the three most common obstetric conditions leading to maternal mortality. Moreover, thrombocytopenia is a known risk factor for PPH, but the platelet count levels considered to be significant risk factors vary across institutions. Mild thrombocytopenia, defined as a platelet count between 100,000 and 149,999 cells/microliter, remains controversial as a potential risk factor for PPH. This study aimed to investigate the relationship between mild thrombocytopenia and the increased risk of postpartum hemorrhage. A retrospective cohort study was conducted among pregnant women of all ages who delivered at Trang Hospital between October 2019 and July 2024. The study included singleton pregnancies between 37 and 41 weeks and 6 days, with nulliparous women as participants. Participants were divided into two groups, comprising 1,200 women with normal platelet counts (≥150,000 cells/microliter) and 120 women with mild thrombocytopenia were included. The results showed that women with mild thrombocytopenia had a 2.195-fold higher likelihood (95% CI 1.094-4.406, p=0.025) of experiencing PPH compared to those with normal platelet counts. Furthermore, the mild thrombocytopenia group was 2.400 times more likely (95% CI 1.004-5.734, p=0.044) to have an estimated blood loss of 1,000 milliliters or more within 24 hours after childbirth. In conclusion, mild thrombocytopenia increases the risk of postpartum hemorrhage and the likelihood of blood loss ≥1,000 milliliters within 24 hours after delivery compared to women with normal platelet counts.