Excess gestational weight gain is associated with child adiposity among mothers with normal and overweight prepregnancy weight status

Abstract

There are inconsistencies in the literature regarding the association between gestational weight gain (GWG) and child adiposity. GWG is hypothesized to act on child adiposity directly through intrauterine programming and indirectly through birth weight. It is unclear if the relative importance of these pathways differs by prepregnancy BMI status. We analyzed data from 3600 participants of the nationally representative Early Childhood Longitudinal Study-Birth Cohort. Child BMI Z-score was calculated from height and weight measured at 5 y. Using linear regression, controlling for sociodemographics and family lifestyle, we examined prepregnancy BMI-specific associations between GWG and child BMI Z-score. There was a nonlinear association among normal (P < 0.001) and overweight mothers only (P = 0.013), such that GWG beyond the midpoint of the 2009 Institute of Medicine recommendations was associated with a significant increase in child BMI Z-score. After the addition of birth-weight-for-gestational-age and breastfeeding to the model, the association remained among normal-weight mothers (P = 0.005) and was slightly attenuated among overweight mothers (P = 0.09). No significant association was observed between GWG and child BMI Z-score among underweight or obese mothers. We used path analysis to decompose the total effect into direct and indirect effects. This indicated the presence of a stronger direct than indirect effect. In conclusion, low GWG is not associated with BMI Z-score among any prepregnancy BMI group. Excess GWG is associated with an increase in child BMI Z-score among normal and overweight mothers only. Prevention of excess GWG may be a strategy to prevent childhood obesity.

FIGURE 1

Conceptual framework for the relationships between GWG and child adiposity measured at 5 y. Black solid lines represent the indirect effect of gestational weight gain on child adiposity.

FIGURE 2

Adjusted association between GWG and child BMI Z-score at 5 y among underweight (n = 250) (A), normal-weight (n = 2150) (B), overweight (n = 750) (C), and obese (n = 450) (D) mothers. Values are β ± 95% CI. Shaded boxes represent IOM/NRC 2009 recommended ranges. ECLS-B, United States, 2001–2007. All models adjusted for sociodemographic characteristics and unhealthy family lifestyle score. ECLS-B, Early Childhood Longitudinal Study-Birth Cohort; GWG, gestational weight gain; IOM, Institute of Medicine.

FIGURE 3

Total (solid line), direct (short dashed line), and indirect (long dashed line) effect of the relationship between GWG and child BMI Z-score at 5 y among underweight (n = 250) (A), normal-weight (n = 2150) (B), overweight (n = 750) (C), and obese (n = 450) (D) mothers. Shaded boxes represent IOM/NRC 2009 recommended ranges. ECLS-B, United States, 2001–2007. All models adjusted for sociodemographic characteristics and unhealthy family lifestyle score. ECLS-B, Early Childhood Longitudinal Study-Birth Cohort; GWG, gestational weight gain; IOM, Institute of Medicine.