LAUSR

BACKGROUND Childhood obesity is an important public health problem, which may lead to increase risk of obesity in adulthood. The relationship between the incidence of obesity and the mode of delivery is not clear. Cesarean section（CS） may be one of the risk factors of obesity in children. We investigated the relationship between the mode of delivery of pregnant women and the risk of overweight/obesity in children of all ages from 1 to 4 years. METHODS Registered in the maternal and child registration system of Xiamen city, newborns born between January 2011 and December 2012 were followed up to 4 years old. RESULTS 9964 cases were included in the study, of which 3462 cases (34.7%) were cesarean deliveries. From 1 to 4 years old, BMI Z-scores and the risk for overweight/obesity of children delivered by CS was higher than by the vagina. Longitudinal analysis of anthropometric assessed during study visits from 1 to 4 years offspring exposed to CS showed that after adjustment for kinds of effect factors, the changes in BMI Z-scores were 0.04 (95% CI 0.01 to 0.09，P=0.003), significantly higher than vaginal delivery, and the risk incidence of overweight/obesity increased 8% in CS offspring, OR=1.08(1.01 to 1.21, P<0.05). CONCLUSION The mode of cesarean delivery is related to the risk of overweight and obesity in children aged 1 to 4. When pregnant women choose cesarean delivery without medical indications, they should be concerned that their offspring may have a higher risk of obesity.