CHANGES IN BLOOD VELOCITIES OF FETAL CIRCULATION IN ASSOCIATION WITH FETAL HEART-RATE ABNORMALITIES - EFFECT OF SUBLINGUAL ADMINISTRATION OF NIFEDIPINE

Nifedipine has been used to treat hypertension in pregnancy, and does not influence fetal or uteroplacental circulations in patients with pr eeclampsia. A 29-year-old multi-gravid woman presented at 32 weeks' ge station with significant elevation of her blood pressure. After sublin gual administration of nifedipine, the blood pressure decreased from 2 08/122 to 136/96 mm Hg at 30 minutes. in her growth-retarded fetus wit h abnormal flow velocity waveforms, pulsatility index values for middl e cerebral artery and umbilical artery did not change; however, peak s ystolic velocities, end-diastolic velocities, and time-averaged mean p eak velocities for these arteries became significantly elevated. Simul taneously, severe variable decelerations and late decelerations occurr ed. The adverse effect of nifedipine on fetal circulation might occur in a growth-retarded fetus with abnormal flow velocity waveforms.