Effect of dihydralazine on the fetus in the treatment of maternal hypertension.

The effect on the fetus of lowering the maternal blood pressure with intravenous dihydralazine was studied in 33 patients with diastolic blood pressure of 110 mmHg or more. Nineteen patients showed fetal heart rate (FHR) decelerations coinciding with a fall in blood pressure. Thirteen of the 19 patients had growth-retarded fetuses, while only 1 of 14 patients who showed no FHR changes had a growth-retarded fetus (P greater than .005). Continuous FHR monitoring during the administration of dihydralazine helped identify the compromised fetus if it had been unrecognized at other observations.