Huh, SusannaRifas-Shiman, SherylZera, ChloeEdwards, Janet W. RichOken, EmilyWeiss, ScottGillman, Matthew2016-05-162012Huh, S. Y., S. L. Rifas-Shiman, C. A. Zera, J. W. R. Edwards, E. Oken, S. T. Weiss, and M. W. Gillman. 2012. Delivery by caesarean section and risk of obesity in preschool age children: A prospective cohort study. Archives of Disease in Childhood 97, no. 7: 610–616. doi:10.1136/archdischild-2011-301141.0003-9888http://nrs.harvard.edu/urn-3:HUL.InstRepos:27003770Objective: To examine whether delivery by caesarean section is a risk factor for childhood obesity. Design: Prospective pre-birth cohort study (Project Viva). Setting: Eight outpatient multi-specialty practices based in the Boston, Massachusetts area. Participants: We recruited women during early pregnancy between 1999 and 2002, and followed their children after birth. We included 1255 children with body composition measured at 3 years of age. Main outcome measures: Body mass index (BMI) z-score, obesity (BMI for age and sex ≥ 95th percentile), and sum of triceps + subscapular skinfold thicknesses, at 3 years of age. Results: 284 children (22.6 percent) were delivered by caesarean section. At age 3, 15.7% of children delivered by caesarean section were obese, compared with 7.5% of children born vaginally. In multivariable logistic and linear regression models adjusting for maternal pre-pregnancy BMI, birth weight, and other covariates, birth by caesarean section was associated with a higher odds of obesity at age 3 (OR 2.10, 95%CI 1.36 to 3.23), higher mean BMI z-score (0.20 units, 95% CI 0.07 to 0.33), and higher sum of triceps + subscapular skinfold thicknesses (0.94 mm, 95% CI 0.36 to 1.51). Conclusions: Infants delivered by caesarean section may be at increased risk of childhood obesity. Further studies are needed to confirm our findings and to explore mechanisms underlying this association.en-USJournal Article2016-05-1610.1136/archdischild-2011-301141