Maternal weight and its association with risk of overweight in offspring: a trajectory analysis from a birth cohort in China.

Abstract

Most studies on the association of maternal pregnancy weight with offspring weight trajectory have a short follow-up time. This study aimed to explore the associations of maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG) with childhood weight trajectories in a 7-year birth cohort. A total of 946 mother-child pairs (467 boys and 479 girls) from a longitudinal birth cohort in TianjinCity, China, were included in this study, ranging from pregnancy to offspring at 7years. The outcome variable was defined as overweight or not overweight in offspring at the last round. A group-based trajectory model was applied to identify childhood BMI trajectory groups. Five discrete BMI trajectory groups were identified and characterized as constant underweight (25.2%), constant normal weight (42.8%), and high or increasing trajectory [at risk of overweight (16.9%), progressive overweight (11.0%) and progressive obesity (4.1%)]. Maternal prepregnancy overweight was associated with 1.72 (95% CI 1.14-2.60, P = 0.01) to 4.02 (95% CI 1.94-8.36, P < 0.001) times the risk of all high or increasing trajectory groups, and excessive GWG was related to groups at risk of overweight [relative risk ratio (RRR) 2.09, 95% CI 1.27-3.46, P = 0.004] and progressive obesity (RRR 3.33, 95% CI 1.13-9.79, P = 0.029). Children in all high or increasing trajectory groups were associated with greater overweight risk at the last round [risk ratios (RRs) ranged from 3.54 (95% CI 2.53-4.95, P < 0.001) to 6.18 (95% CI 4.05-9.42, P < 0.001)]. Maternal prepregnancy overweight and excessive gestational weight gain were associated with increasing or high-level childhood body mass index trajectories as well as a greater risk of overweight at 7 years.