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 preeclampsia. A 29-year-old multi-gravid woman presented at 32 weeks' gestation with significant elevation of her blood pressure. After sublingual administration of nifedipine, the blood pressure decreased from 208/122 to 136/96 mm Hg at 30 minutes. in her growth-retarded fetus with abnormal flow velocity waveforms, pulsatility index values for middle cerebral artery and umbilical artery did not change; however, peak systolic velocities, end-diastolic velocities, and time-averaged mean peak velocities for these arteries became significantly elevated. Simultaneously, severe variable decelerations and late decelerations occurred. The adverse effect of nifedipine on fetal circulation might occur in a growth-retarded fetus with abnormal flow velocity waveforms.