The Effect of Oral Ketanserin on Fetal Heart Rate Parameters.

> Objective: To determine the effects of ketanserin given from early in the midtrimester of pregnancy on fetal heart rate parameters later in pregnancy. Methods: Patients with diastolic blood pressure persistently higher than 80 mm Hg between 12 and 20 weeks' gestational age were randomized to receive either ketanserin or placebo. Both groups also got 75 mg of aspirin per day. The fetal heart rate was monitored once every fortnight from 28 weeks' gestation and weekly from 36 weeks onward. Recordings were made with the Sonicaid System 8000 and continued until the Dawes and Redman criteria were met. Results: The Dawes and Redman criteria were met within 10 min in 54% of recordings in both study groups, whereas they were not met in 4.5 and 3.3% of recordings in the ketanserin group and placebo group, respectively (P = 0.58). The mean time to meet these criteria duration per recording was 16.9 min in the ketanserin group and 16.2 min in the placebo group (P = 0.83). There were no significant differences between the two study groups in fetal heart rate variability, accelerations, or decelerations before 38 weeks' gestation. Thereafter the mean minute range and short-term and baseline variability were significantly higher in the ketanserin group, and significantly more accelerations of the fetal heart were recorded in the ketanserin group. Conclusions. Ketanserin does not influence the fetal heart rate adversely and may even be associated with improved recordings late in pregnancy.