Antihypertensive treatment and fetal welfare in essential hypertension in pregnancy: a retrospective survey of experience with various regimes at National Women's Hospital, Auckland, 1970-80.

A series of 184 pregnancies in 161 hypertensive women was classified according to the regimen of antihypertensive treatment used during pregnancy. In 72 pregnancies management was with bed rest alone, attaining a mean gestation of 37.8 +/- 0.4 weeks, a mean birthweight of 2941 +/- 97 g with 38 percent of infants below the 25th percentile. Late deterioration of hypertension with development of proteinuria occurred in 16.6 percent with fetal mortality of 6.9 percent. Antihypertensive therapy involved methyldopa, thiazide diuretics, sympathetic ganglion blockers, hydralazine, beta-adrenergic blockers and the combination of oxprenolol and prazosin. Fetal growth was compared in pregnancies that reached term on the various regimens. Significantly better growth was achieved where debrisoquine plus a thiazide were used (3617 +/- 113 g in six subjects) and oxprenolol/prazosin (3411 +/- 72 g in 14 subjects) compared to 11 comparably hypertensive patients on bed rest alone (2975 +/-87 g). Therapy with the ganglion blocker plus thiazide was complicated by the deterioration of hypertension with proteinuria in 37.2 percent of women; this did not occur in patients receiving oxprenolol/prazosin. Maternal age had no effect on fetal growth, but smoking more than 10 cigarettes per day caused significant growth retardation.