Gestational thrombocytopenia and risk of postpartum hemorrhage and severe maternal morbidity: a population-based...

Gestational thrombocytopenia is the most common cause of thrombocytopenia in pregnancy and is traditionally considered a benign condition. However, emerging evidence suggests that even mild reductions in platelet count may increase hemorrhagic risk at delivery. We aimed to evaluate the association between gestational thrombocytopenia and adverse maternal outcomes and examine whether these associations varied by socioeconomic status, race, and insurance type.

We conducted a retrospective cohort study using the New York State Inpatient Database (2016-2020). Gestational thrombocytopenia was identified using ICD-10-CM codes. Propensity score matching (1:4) was performed to balance sociodemographic and clinical covariates. Outcomes included postpartum hemorrhage, blood transfusion, severe maternal morbidity (SMM), and non-transfusion SMM. Stratified analyses were performed by Distressed Communities Index (DCI) category, race, and insurance status.

Among 982,819 deliveries, 17,696 (1.8%) had gestational thrombocytopenia. After matching, gestational thrombocytopenia was associated with higher odds of PPH (OR 1.40; 95% CI 1.30-1.50), transfusion (OR 1.57; 95% CI 1.42-1.73), SMM (OR 1.55; 95% CI 1.41-1.70), and non-transfusion SMM (OR 1.48; 95% CI 1.20-1.84). The association with transfusion and SMM was most pronounced in the advantaged DCI cohort (transfusion OR 1.89; SMM OR 1.90) and among Asian/Pacific Islander patients (transfusion OR 2.47; SMM OR 2.42). No significant differences were observed by insurance status.

Gestational thrombocyoptenia is independently associated with higher odds of PPH, transfusion, and SMM. Although the clinical significance of these associations requires further study, these findings suggest that the hemorrhagic risk associated with gestational thrombocytopenia may be underappreciated and merit consideration in peripartum risk assessment.