Relation between Gestational Thrombocytopenia and the Syndrome of Hemolysis, Elevated Liver Enzymes, and Low Platelet Count (HELLP Syndrome)

Abstract

Objective: To define the clinical features of gestational thrombocytopenia and to determine its relationship to the syndrome of hemolysis, elevated liver enzymes, and low platelet count (HELLP syndrome). Study Design: Retrospective cohort study. We reviewed the records of 24 women with gestational thrombocytopenia among 637 nonpreeclamptic women who had serial determinations of the platelet count during pregnancy between 1992 and 1995. Gestational thrombocytopenia was defined as an antenatal gradual decline in the platelet count to <150 × 10⁹/l in nonpreeclamptic women. The control group consisted of 213 nonpreeclamptic women whose platelet counts were ≥150 × 10⁹/l at –3 to 0 days from delivery and in whom the perinatal serum level of aspartate transaminase (AST) had been determined. Results: The platelet count decreased gradually, from 210 ± 31 × 10⁹/l at <13 weeks’ gestation to 127 ± 24 × 10⁹/l at –3 to 0 days from delivery, in the 24 women with gestational thrombocytopenia. The platelet count was 251 ± 62 × 10⁹/l at –3 to 0 days from delivery in the 213 control women. The serum level of AST was elevated perinatally in 5 (21%) of 24 women with gestational thrombocytopenia compared with 6 (2.8%) of the 213 control subjects (p < 0.001). There had been 28 previous term or near-term pregnancies among 17 women with gestational thrombocytopenia, 14 of which were complicated by gestational thrombocytopenia or a decline in the platelet count by >50 × 10⁹/l; 1 pregnancy was associated with the features typical of the HELLP syndrome. Conclusion: Gestational thrombocytopenia may be a risk factor for the development of the HELLP syndrome and is likely to recur in subsequent pregnancies.