Reduced fetal platelet counts in pregnancies with abnormal Doppler umbilical flow waveforms

Fetal and maternal platelet counts were correlated with antenatal assessment of the umbilical-placental waveform. Forty singleton pregnancies were studied using Doppler ultrasound, and placental resistance was categorized as normal or high according to the systolic/diastolic ratio. We performed platelet counts on maternal and cord blood taken at the time of cesarean section. The high-resistance group had a mean fetal platelet count (218 +/- 53 x 10(3)/microliters) significantly lower than that of the normal-resistance group (314 +/- 76 x 10(3)/microliters) (P less than .001). This difference was evident in both the hypertensive and nonhypertensive subgroups of the high-resistance group. There was no difference in mean maternal platelet counts between the high- and normal-resistance groups.