Baseline fetal heart rates from 15 to 38 weeks gestation in normotensive and hypertensive pregnancies.

To determine whether the fetal heart behaves differently in normotensive and hypertensive pregnancies, the changes in baseline fetal heart rate were investigated prospectively from 15 to 38 weeks gestation in 16 women who were normotensive at the time of booking in the antenatal clinic. Fetal heart rate recordings were made ultrasonically, and were computer-processed by the programs TELEPLOT and BASELINE. Those women who remained normotensive exhibited a decrease of fetal heart rate with advancing gestational age, but this did not occur in the six women who eventually developed hypertension.