Abstract
Introduction—
Few studies have investigated the relationship between delivery mode in the U.S. and the risk of overweight and obesity in the offspring. The findings from these studies have not been consistent.
Hypothesis—
We assessed the hypothesis that children born by cesarean section (C-section) compared with those born vaginally were at an increased risk of overweight and obesity in grade six.
Methods—
Data were obtained from Phase I to Phase IV of the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development. Subjects with complete data through stage 3 (from year 1991 to 2005), when the children were in grade six, were included in this study (n=917). Multiple logistic regression was used to adjust for potential confounding by the maternal factors of age, education, poverty status, living status, depression, breastfeeding, and smoking status during pregnancy and the child factors of sex, race, birth weight, physical activity, total TV time, and video/computer game time. The association between C-section and childhood overweight and obesity was evaluated.
Results—
In grade six, 41.4% (77 of 186) of children delivered by C-section were overweight compared with 32.2% (235 of 731) of children born vaginally while 24.7% (46 of 186) of children delivered by C-section were obese compared with 17.0% (124 of 731) of children born vaginally (both p<0.05). After adjustment for potential confounders, children delivered by C-section compared to vaginal delivery had about twice the risk of being overweight (OR=1.85, 95% CI=1.26-2.71) or obese ((OR=1.87, 95% CI=1.19-2.94). However, after examining the association separately by sex, males delivered by C-section had an increased risk only for being obese (OR=2.56, 95% CI=1.35-4.85) while females delivered by C-section had an increased risk only for being overweight (OR=1.99, 95% CI=1.16-3.40). It was also found that lower maternal education and higher child birth weight were both associated with increased risk of overweight and obesity in sixth grade children.
Conclusions—
In conclusion, C-section was associated with an increased risk of overweight and obesity in children in grade six, and the relationship varied by sex. Additional longitudinal studies are warranted to examine the long-term effects of delivery mode on the risk of childhood overweight and obesity.