Perinatal outcome in growth-restricted fetuses: do hypertensive and normotensive pregnancies differ?

To test the hypothesis that fetal growth restriction (FGR) associated with a maternal hypertensive disorder results in worse perinatal outcome than FGR in pregnancies without maternal hypertension.

All consecutive, singleton, nondiabetic, small for gestational age (SGA) deliveries (birth weight at or below the tenth percentile for gestational age) in a 15-year computerized data base were analyzed for pregnancy outcome. Perinatal outcome was compared after stratification by presence or absence of hypertensive disorders and by gestational age at delivery.

Eleven thousand two hundred twenty-seven SGA pregnancies were analyzed. The morbidity and mortality profiles differed between hypertensive and normotensive pregnancies delivered preterm and those delivered at term. Perinatal mortality was significantly higher in the normotensive than in the hypertensive group in preterm deliveries (30.3 versus 18.7%, odds ratio [OR] 1.9 [confidence interval (CI) 1.3-2.9]). At term, hypertensive pregnancies demonstrated significantly higher mortality than normotensive pregnancies (4.6 versus 1.9%, OR 2.42 [95% CI 1.7-3.4]). In both preterm and term gestations, cesarean rates were significantly higher in hypertensive pregnancies than in normotensive pregnancies. Using logistic regression analysis, hypertension was independently associated with a 39% reduction in risk of perinatal mortality preterm, compared with a twofold increased risk of perinatal mortality at term.

Before term, FGR in normotensive women resulted in significantly higher perinatal mortality than FGR in hypertensive women. In contrast, at term, FGR in pregnancies complicated by hypertension had poorer perinatal outcomes than FGR in normotensive women.