Hypertensive disorders in twin versus singleton gestations

OBJECTIVE: This study was undertaken to compare rates and severity of gesta tional hypertension and preeclampsia, as well as perinatal outcomes when th ese complications develop, between women with twin gestations and those wit h singleton gestations. STUDY DESIGN: This was a secondary analysis of prospective data from women with twin (n = 684) and singleton (n = 2946) gestations enrolled in two sep arate multicenter trials of low-dose aspirin for prevention of preeclampsia . End points were rates of gestational hypertension, rates of preeclampsia, and perinatal outcomes among women with hypertensive disorders. RESULTS: Women with twin gestations had higher rates of gestational hyperte nsion (relative risk, 2.04; 95% confidence interval, 1.60-2.59) and preecla mpsia (relative risk, 2.62; 95% confidence interval, 2.03-3.38). In additio n, women with gestational hypertension during twin gestations had higher ra tes of preterm delivery at both <37 weeks' gestation (51.1% vs 5.9%; P < .0 001) and <35 weeks' gestation (18.2% vs 1.6%; P < .0001) and also had highe r rates of small-for-gestational-age infants (14.8% vs 7.0%; P = .04). More over, when outcomes associated with preeclampsia were compared. women with twin gestations had significantly higher rates of preterm delivery at <37 w eeks' gestation (66.7% vs 19.6%; P < .0001), preterm delivery at <35 weeks' gestation (34.5% vs 6.3%; P < .0001), and abruptio placentae (4.7% vs 0.7% ; P = .07). In contrast, among women with twin pregnancies, those who remai ned normotensive had more adverse neonatal outcomes than did those in whom hypertensive complications developed. CONCLUSIONS: Rates for both gestational hypertension and preeclampsia are s ignificantly higher among women with twin gestations than among those with singleton gestations. Moreover, women with twin pregnancies and hypertensiv e complications have higher rates of adverse neonatal outcomes than do thos e with singleton pregnancies.