Associations of maternal obesity with blood pressure and the risks of gestational hypertensive disorders. The Generation R Study

Abstract

Objective: We examined the associations of maternal prepregnancy BMI and gestational weight gain with SBP and DBP in different trimesters of pregnancy and the risks of pregnancy-induced hypertension and preeclampsia in a population-based prospective cohort study among 6902 mothers.

Methods: Information about maternal weight just before pregnancy was obtained by questionnaires. Maternal anthropometrics and blood pressure were measured in each trimester. Information about gestational hypertensive disorders was available from medical records.

Results: As compared to mothers with a normal weight, maternal obesity (BMI 30-34.9 kg/m) and morbid obesity (BMI ≥35 kg/m) were associated with higher first trimester SBP [differences for obese women and morbidly obese women: 10.80 mmHg (95% confidence interval: 9.44-12.17) and 13.07 mmHg (95% confidence interval: 10.91-15.23), respectively] and DBP [differences for obese women and morbidly obese women: 8.69 mmHg (95% confidence interval: 7.63-9.74) and 13.12 mmHg (95% confidence interval: 11.44-14.79), respectively]. Similar differences were observed during second and third trimester. The risks of pregnancy-induced hypertension and preeclampsia were increased among obese mothers [odds ratio 4.67 (95% confidence interval: 3.07-7.09) and odds ratio 2.49 (95% confidence interval: 1.29-4.78), respectively] and morbidly obese mothers [odds ratio 11.34 (95% confidence interval: 6.80-18.86) and odds ratio 3.40 (95% confidence interval: 1.39-8.28), respectively]. Maternal weight gain was associated with the risk of pregnancy-induced hypertension.

Conclusion: Maternal obesity and morbid obesity are strongly associated with blood pressure in each trimester, and increased risks of gestational hypertensive disorders.