Association of preeclampsia with high birth weight for gestational age

OBJECTIVE: The purpose of this study was to examine the effect of gestation al hypertension and preeclampsia on fetal growth. STUDY DESIGN: A retrospective cohort study was conducted on the basis of 97 ,270 pregnancies delivered between 1991 and 1996 in 35 hospitals in norther n and central Alberta, Canada. Univariate and multivariate logistic analyse s were performed to examine the impact of preeclampsia and gestational hype rtension on high-birth-weight (greater than or equal to 4200 g), large-for- gestational-age, low-birth-weight (<2500 g), and small-for-gestational-age babies. RESULTS: The rate of high-birth-weight fetuses in women with gestational hy pertension (7.3%) was higher than in those with normal blood pressure (5.6% ). After we controlled for confounders, the adjusted odds ratio of high bir th weight was 1.44 (95% confidence interval, 1.21-1.70) in women with gesta tional hypertension. Preeclampsia was also associated with a statistically nonsignificant (P = .054) increased risk of high birth weight (adjusted odd s ratio, 1.40; 95% confidence interval 0.99-1.98). The rate of large-for-ge stational-age babies was significantly higher in women with gestational hyp ertension (4.5%) and preeclampsia (4.7%) than in those with normal blood pr essure (2.2%), with adjusted odds ratios of 1.50 (95% confidence interval, 1.22-1.85) for gestational hypertension and 1.87 (95% confidence interval, 1.31-2.67) for preeclampsia. Concurrently, women who had gestational hypert ension were also at higher risk of having low-birth-weight (adjusted odds r atio, 2.4; 95% confidence interval, 2.13-2.93) and small-for-gestational-ag e (adjusted odds ratio, 2.04; 95% confidence interval, 1.68-2.48) babies. W omen with preeclampsia were also at markedly higher risk of having low-birt h-weight (adjusted odds ratio, 4.14; 95% confidence interval, 3.32-5.15) an d small-for-gestational-age (adjusted odds ratio, 2.56; 95% confidence inte rval, 1.92-3.41) babies. CONCLUSIONS: There is a significant association of preeclampsia and gestati onal hypertension with large-for-gestational-age infants, in addition to a significant association with low-birth-weight and small-for-gestational-age infants. This study challenges the currently held belief that reduced uter oplacental perfusion is the unique pathophysiologic process in preeclampsia .