Background: Hypertensive disorders complicating pregnancy increase the risk of adverse obstetric and perinatal outcomes.
Aim: To assess the impact of age, education, family history of cardiovascular disease, pre-pregnancy overweight/obesity and weight gain during pregnancy on hypertensive disorders, among primiparae and multiparae.
Subjects and methods: In a birth cohort study, puerperae were consecutively recruited at public maternity units of Porto, Portugal (2005-2006). The study included 6952 women with singleton births and complete data. Hypertensive disorders included chronic hypertension, gestational hypertension or pre-eclampsia/eclampsia.
Results: Overall, hypertensive disorders affected 4.6% of single pregnancies and were associated with older age, lower education, family history of cardiovascular disease and excessive weight before and during pregnancy, similarly in primiparae and multiparae. Approximately 50% of cases among primiparae and 70% among multiparae were attributable to the joint effect of pregnancies after 34 years of age, education below 12 years, family history of cardiovascular disease and excessive weight before and during pregnancy.
Conclusion: The risk factors explained a high proportion of hypertensive disorders during pregnancy. Excessive weight before and during pregnancy had a very large contribution. The substantial joint effect of the risk factors suggests that interventions focusing on these risk factors should be part of pre-conceptional and pre-natal care.