Cesarean delivery is associated with an increased risk of obesity in adulthood in a Brazilian birth cohort study.

The authors initiated a birth cohort study in RibeirÃƒÂ£o Preto, southeastern Brazil, in 1978. A randomly selected sample of 2057 subjects from the original cohort was reassessed in 2002-2004. Type of delivery, birth weight, maternal smoking, and schooling were obtained after birth. The following data from subjects were collected at 23-25 y of age: body mass index (BMI; in kg/m(2)), physical activity, smoking, and income. Obesity was defined as a BMI Ã¢â€°Â¥30. A Poisson multivariable model was performed to determine the association between cesarean delivery and BMI. RESULTS: The obesity rate in adults born by cesarean delivery was 15.2% and in those born by vaginal delivery was 10.4% (P = 0.002). Adults born by cesarean delivery had an increased risk (prevalence ratio: 1.58; 95% CI: 1.23, 2.02) of obesity at adulthood after adjustments. CONCLUSION: The authors hypothesize that increasing rates of cesarean delivery may play a role in the obesity epidemic worldwide.