Maternal outcomes in pregnancies complicated by obesity

OBJECTIVE: To investigate the relationship between prepregnancy obesity and maternal outcomes. METHODS: A 15-year, population-based cohort study using the Nova Scotia Atlee Perinatal Database compared maternal outcomes in obese and nonobese women. Prepregnancy weight of 55-75 kg was considered nonobese, and weight greater than 90 kg was considered obese. Obese women were categorized into moderate obesity (90-120 kg) and severe obesity (> 120 kg) groups. Univariate and multivariable logistic regression analysis was performed, and odds ratios (ORs), adjusted ORs, and 95% confidence intervals (CIs) were calculated. P < .05 was considered statistically significant. RESULTS: In 142,404 singleton pregnancies, 10,134 (7.2%) women were identified as obese (moderate obesity 92.3%, severe obesity 7.7%). The proportion of women in the obese categories increased from 3.2% in 1988 to 10.2% in 2002. Moderately obese women had an increased risk of pregnancy-induced hypertension (PIH) (adjusted OR 2.38, 95% CI 2.24-2.52), antepartum venous thromboembolism (adjusted OR 2.17, 95% CI 1.30-3.63), labor induction (adjusted OR 1.94, 95% CI 1.86-2.04), cesarean delivery (adjusted OR 1.60, 95% CI 1.53-1.67), and wound infection (adjusted OR 1.67, 95% CI 1.38-2.00). Severely obese women had an increased risk of PIH (adjusted OR 3.00, 95% CI 2.49-3.62), antepartum venous thromboembolism (adjusted OR 4.13, 95% CI 1.26-13.54), induction of labor (adjusted OR 2.77, 95% CI 2.39-3.21), cesarean delivery (adjusted OR 2.46, 95% CI 2.15-2.81), anesthesia complications (adjusted OR 2.01, 95% CI 1.33-3.06), and wound infection (adjusted OR 4.79, 95% CI 3.30-6.95). This implies that, relative to nonobese women, there was 1 excess case of PIH per 10 moderately obese women and 1 per 7 severely obese women. For antepartum venous thromboembolism, there was 1 excess case per 857 moderately obese women and 1 per 321 severely obese women. CONCLUSION: Prepregnancy maternal obesity increases the risk of PIH, antepartum venous thromboembolism, labor induction, cesarean delivery, and wound infection.