[Relations between hypertensive disorders in pregnancy and subsequent risk of early-term birth: a birth cohort study].

Objective: To evaluate the relations between hypertensive disorders (HDP) in pregnancy and early-term birth. Methods: A total of 3 474 pregnant women were consecutively recruited. Demographic information was collected in early pregnancy. HDP was diagnosed in the first, second and third trimesters, respectively. On the basis of precise evaluation on gestation age, early-term birth was defined as gestational age of 37-38 weeks+6 days. Logistic regression models were conducted to examine the associations between HDP and early-term birth. Results: The current study included 3 260 pregnant women, with the rates of HDP, pregnancy-induced hypertension syndrome and pre-eclampsia as 6.0% ( n =194), 4.2% ( n =137) and 1.8% ( n =57), respectively. After controlling for potential confounders, no significant differences between pregnancy-induced hypertension syndrome and earlyterm birth ( OR =1.49, 95% CI : 0.94-2.36) were found. Pre-eclampsia appeared to have increased the risk of early-term birth ( OR =4.46, 95% CI : 2.09-9.54). Conclusion: Pre-eclampsia could significantly increase the risk of early-term birth. This finding suggested that early detection and intervention programs were helpful in reducing the risk of early-term birth.