Severe Thrombocytopenia in Pregnancy: Etiology, Management, and Outcomes Across Platelet Count Categories

Background/Objectives: Severe thrombocytopenia (platelet count ≤ 50,000/µL) is a diagnostically heterogeneous condition during pregnancy, encompassing obstetric and non-obstetric etiologies that require distinct management approaches. The aims of this study were to determine the etiological distribution of severe thrombocytopenia during pregnancy and to evaluate its management strategies and perinatal outcomes in a tertiary perinatology center. Methods: This retrospective cohort study included 203 pregnant women with severe thrombocytopenia (platelet count ≤ 50,000/µL) stratified into three groups: Group A (30,000 < platelet count ≤ 50,000/μL, n = 123), Group B (10,000 < platelet count ≤ 30,000/μL, n = 54), and Group C (<10,000/µL, n = 26). Demographic characteristics, etiological diagnoses, treatment modalities, and perinatal outcomes were evaluated. Results: The etiological distribution varied significantly across severity groups (p = 0.001). HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome was the most common cause overall (36.5%) and predominated in milder thrombocytopenia (Group A: 40.7%; Group B: 42.6%), whereas non-obstetric etiologies, such as immune thrombocytopenia (ITP), were significantly more frequent in Group C (57.7%). Treatment intensity increased with severity, with 79.7% of Group A requiring no intervention compared to only 26.9% of Group C (p = 0.001). Gestational age at delivery (median 37 weeks, p = 0.587) and birth weight (mean 2547 ± 968 g, p = 0.191) were comparable across severity groups. Minimum platelet count showed no significant correlation with delivery timing, birth weight, or hemoglobin decline. Conclusions: Severe thrombocytopenia in pregnancy exhibits distinct etiological patterns that vary according to platelet count severity. Favorable perinatal outcomes are achievable with appropriate diagnosis and management in specialized centers, underscoring the importance of comprehensive diagnostic evaluation rather than relying solely on platelet count thresholds for clinical decision-making.