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

Thrombocytopenia detected during pregnancy addresses the issue of its mecha nism and of the possible occurrence of neonatal thrombocytopenia. To furthe r investigate these issues, 50 women referred to us because of thrombocytop enia detected during pregnancy (platelet count, <150 x 10(9)/L), were exten sively studied, as well as their offspring. Among these thrombocytopenic wo men, we used the threshold of 70 x 10(9)/L to differentiate between mild an d severe thrombocytopenia. Whatever the severity of thrombocytopenia, we fo und 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 thr ombocytopenic, either at birth or during the first week of life. Neonatal t hrombocytopenia could only be predicted in multiparous women, on the basis of previous neonatal thrombocytopenia in older siblings, and/or when matern al platelet life span study, performed before pregnancy, had evidenced an a utoimmune thrombocytopenia (AITP)-like profile. These results suggest that, in case of pregnancy-associated thrombocytopenia, familial and immunologic al studies, combined with postdelivery iterative platelet counts, should be performed to properly characterize the thrombocytopenia. Moreover, the pla telet count of the neonate should be carefully assessed at birth and during the following days, a platelet life span study should be performed after d elivery in the mother, because these two parameters are likely to bring val uable information regarding the forthcoming pregnancies and the risk of neo natal thrombocytopenia. (C) 1998 by The American Society of Hematology.