[Pre-pregnancy BMI, gestational diabetes and different indicators of childhood obesity at the age of four: a prospective cohort study].

Objective: To examine the relationship between pre-pregnancy BMI, gestational diabetes (GDM) and different indicators of childhood obesity at the age of 4. Methods: Based on Ma'anshan Birth Cohort Study, singleton children who were born in Ma'anshan of Anhui province from October 2013 to April 2015, were followed for 4 years, consecutively. During the first questionnaire survey, data including pre-pregnancy weight, height and socio-demography were collected. During 24-28 week of gestation, 75 g oral glucose tolerance test was conducted for them. Childhood height, weight, waist circumference and body composition were measured at the age of 4. Comparisons between groups were performed using chi-square test, analysis of variance or t-test. The relationship between pre-pregnancy overweight/obesity, GDM and childhood obesity-related characteristics were analyzed by logistic regression model and generalized linear model analysis. Results: The prevalence rates of overweight and obesity in children at the age of 4 were 13.08% and 6.03%, respectively. After adjustment for characteristics related to mothers and their children, significantly increased risk of obesity (OR=3.27, 95%CI: 2.15-4.98), larger waist circumference (OR=2.32, 95%CI: 1.72-3.14) and higher waist-to-weight ratio (OR=2.29, 95%CI: 1.73-3.02) were seen in the offspring of women with pre-pregnancy overweight/obesity. Body composition (skeletal muscle, body fat, body fat percentage) of the offspring were strongly correlated with pre-pregnancy overweight/obesity of the mothers (P<0.05). Maternal GDM was associated with higher risk of childhood obesity (OR=1.78, 95%CI: 1.14-2.79), on mothers without GDM during pregnancy. However, neither larger waist circumference, or higher waist-to-weight ratio seemed to increase the risk. Moreover, maternal GDM was not associated with body composition measures (skeletal muscle, body fat, body fat percentage). Conclusion: Pre-pregnancy BMI and maternal GDM were independent risk factors for obesity in 4-year-old children, and pre-pregnancy BMI was correlated with various indicators of body composition in children.