Perinatal mortality and delivery patterns are compared for 4035 gravidas who were prescribed diuretic drugs during pregnancy and 13,103 gravidas who were not. Diuretic drugs were prescribed primarily for edema; gravidas with hypertensive disorders were excluded. The 2 groups, differing in both condition and drug excluded. The 2 groups, differing in both condition and drug usage, had significantly different gestational age distributions. The gravidas prescribed diuretic drugs delivered infants of higher mean birthweight and had significantly higher incidences of induction of labor, stimulation of labor, uterine inertia, and meconium staining. Their perinatal mortality rates also tended to be higher. The findings support the contention that higher risk is associated with one or more factors differentiating the 2 groups, namely, edema, undefined factors associated with edema, or the consumption of a diuretic drug.