Pregnancy-associated thrombocytopenia revisited: assessment and follow-up of 50 cases.

Thrombocytopenia detected during pregnancy addresses the issue of its mechanism and of the possible occurrence of neonatal thrombocytopenia. To further investigate these issues, 50 women referred to us because of thrombocytopenia detected during pregnancy (platelet count, <150 x 10(9)/L), were extensively studied, as well as their offspring. Among these thrombocytopenic women, we used the threshold of 70 x 10(9)/L to differentiate between mild and severe thrombocytopenia. Whatever the severity of thrombocytopenia, we found biological features of an autoimmune disorder in 48% of the women, and chronic thrombocytopenia in 55%. A familial thrombocytopenia was evidenced in 1 case. These 50 women gave birth to 63 neonates, among whom 24 were thrombocytopenic, either at birth or during the first week of life. Neonatal thrombocytopenia could only be predicted in multiparous women, on the basis of previous neonatal thrombocytopenia in older siblings, and/or when maternal platelet life span study, performed before pregnancy, had evidenced an autoimmune thrombocytopenia (AITP)-like profile. These results suggest that, in case of pregnancy-associated thrombocytopenia, familial and immunological studies, combined with postdelivery iterative platelet counts, should be performed to properly characterize the thrombocytopenia. Moreover, the platelet count of the neonate should be carefully assessed at birth and during the following days, a platelet life span study should be performed after delivery in the mother, because these two parameters are likely to bring valuable information regarding the forthcoming pregnancies and the risk of neonatal thrombocytopenia.