Thrombocytopenia at delivery: a prospective survey of 6715 deliveries.

Thrombocytopenia occurred in 513 (7.6%) of 6715 consecutive deliveries that occurred in our hospital over a 3-year interval. The patients with thrombocytopenia could be divided into three groups. The largest group (65.1%) consisted of healthy women whose thrombocytopenia was incidentally detected. The next group of patients (13.1%) was composed of healthy women who had an obstetric or medical condition such as diabetes or premature labor. No mother or infant in either group had excessive bleeding, and no infant had a cord platelet count less than 50 x 10(9) per liter. The last group (21%) was composed of hypertensive patients and patients with immune thrombocytopenia. Two infants in this group had cord platelet counts less than 50 x 10(9) per liter, but neither had bleeding. This study indicates that incidental thrombocytopenia in an otherwise well woman at term is the most frequent type of thrombocytopenia and poses no apparent risk for mother or infant at delivery.