Risk of Overweight and Obesity in Children under 6 Years Old Following Cesarean Delivery: A Systematic Review and Meta-analysis of Cohort Studies

Background: Cesarean delivery is considered as a potential risk factor for childhood overweight/obesity; however, its risk magnitude remains unknown. To estimate the risk of being overweight/obese in children under 6 years old following cesarean delivery. Methods Three English and two Chinese databases were searched. The quality of studies was appraised using the Newcastle-Ottawa Scale. Meta-analyses were conducted to estimate the pooled rates and relative risk (RR) of overweight/obesity, with RR estimates to compare the risks between children delivered by cesarean section and children delivered vaginally under 6 years old. Results Eighteen cohort studies with a total of 125,042 children under 6 years old were included. Of them, 33,551 children were delivered by cesarean section. The rates of pooled estimate of overweight combined with obesity, overweight alone, and obesity alone in children delivered by cesarean section were 18.2%, 14.1%, and 8.6%, respectively, while corresponding rates in children delivered vaginally were 14.0%, 12.5%, and 6.6%. Cesarean delivery was associated with significantly increased risks of childhood overweight combined with obesity (RR 1.18, 95% confidence interval [CI] 1.13–1.23), overweight alone (RR 1.09, 95% CI 1.02–1.17), and obesity alone (RR 1.26, 95% CI 1.13–1.40) as compared with vaginal delivery. Subgroup analyses showed a low degree of heterogeneity among all subgroups. Sensitivity analysis showed that overall estimates remained essentially the same when omitting one study at a time. Conclusion Children delivered by cesarean section may have an increased risk of overweight and / or obesity than children delivered vaginally in the first 6 years of life.