Fetal platelet counts in the obstetric management of immunologic thrombocytopenic purpura.

The optimal method of infant delivery for gravida women with immunologic thrombocytopenic purpura (ITP) is controversial because of the unpredictability of the fetus developing thrombocytopenia and the uncertainty of the relation between vaginal birth and intracranial hemorrhage in thrombocytopenic infants. We have employed the technique of platelet counts on fetal scalp blood obtained prior to or early in the course of labor in 12 patients with ITP. A count of 50,000/cu mm, selected on the basis of literature review and retrospective analysis of our own experience, was used to define fetal thrombocytopenia. Three thrombocytopenic fetuses were delivered by cesarean section. Trial labor was permitted in the other nine cases in which fetal scalp platelet count exceeded 50,000/cu mm. The outcome was good in all instances. If cesarean section is to be employed in ITP patients to obviate the potential danger of fetal hemorrhage with vaginal delivery, the use of platelet counts of fetal scalp blood seems to provide the most rational basis for management at present.