Effects of nifedipine on umbilical artery velocity waveforms in healthy human fetuses

Abstract

The purpose of this investigation was to analyze the changes in umbilical artery (UA) velocity waveforms after administration of nifedipine in 30 healthy pregnant women. The effects on fetal and maternal heart rates and maternal arterial pressure were also analyzed. The patients included in this double blind study received sublingually either 10 mg of nifedipine or a placebo. A transient fall of the UA resistance (as expressed by the pulsatility index) occurred 15 min after nifedipine administration, but resistance returned to control values after 90 min. Maternal heart rate increased after nifedipine administration and returned toward the control value by 45 min. Fetal heart rate and maternal mean arterial pressure did not change significantly. These data suggest a possible use of nifedipine to normalize the UA velocity waveform in pregnancies complicated by hypertension and fetal growth retardation.