Increasing pre-pregnancy body mass index is predictive of a progressive escalation in adverse pregnancy outcomes

Abstract

Objective: To evaluate the association between pre-pregnancy body mass index (BMI) and adverse pregnancy outcomes using a large administrative database. Methods: Retrospective cohort study of California women delivering singletons in 2007. The association between pre-pregnancy BMI category and adverse outcomes were evaluated using multivariate logistic regression. Results: Among 436,414 women, increasing BMI was associated with increasing odds of adverse outcomes. Obese women (BMI = 30–39.9) were nearly 3x more likely to have gestational diabetes (OR = 2.83, 95% CI = 2.74–2.92) and gestational hypertension/preeclampsia (2.68, 2.59–2.77) and nearly twice as likely to undergo cesarean (1.82, 1.78–1.87), when compared to normal BMI women (BMI = 18.5–24.9). Morbidly obese women (BMI ≥ 40) were 4x more likely to have gestational diabetes (4.72, 4.46–4.99) and gestational hypertension/preeclampsia (4.22, 3.97–4.49) and nearly 3x as likely to undergo cesarean (2.60, 2.46–2.74). Conclusion: There is a strong association between increasing maternal BMI and adverse pregnancy outcomes. This information is important for counseling women regarding the risks of obesity in pregnancy.

Keywords::

• BMI
• gestational diabetes
• gestational hypertension
• preeclampsia
• cesarean delivery
• macrosomia

Acknowledgement

This research was presented at the 31st Annual Scientific Meeting of the Society for Maternal Fetal Medicine, San Francisco, CA, Feb. 10–12, 2011 and was supported by Title V funds received from the California Department of Public Health; Maternal, Child and Adolescent Health Division. Analysis, interpretation, or conclusions reached are those of the authors and not the state of California.

Declaration of Interest: None of the authors have any conflict of interest to disclose.