Gestational weight gain in relation to offspring body mass index and obesity from infancy through adulthood.

OBJECTIVE: Gestational weight gain (GWG) is associated with childhood obesity. We analyzed whether this effect persists into adulthood and is mediated by effects in childhood.

DESIGN: The design of the study a prospective birth cohort study established in 1959-1961.

SUBJECTS: The subjects were offspring (n = 4234 of whom 2485 had information from the last follow-up) of mothers included in 'The Copenhagen Perinatal Cohort' during pregnancy or at birth.

MEASUREMENTS: Information on maternal pre-pregnancy body mass index (BMI), GWG and several potential confounders were collected around delivery. Information on offspring BMI was available from various follow-up examinations from 1 to 42 years of age. The association of GWG with offspring BMI was analyzed by regression models including confounders. Using path analysis, the association of GWG with adult BMI was disentangled into an association mediated through childhood BMI and one independent hereof.

RESULTS: GWG was associated with offspring BMI at all ages. At the age of 42 years (n = 1540), there was an increasing risk of obesity (odds ratio (OR) 1.08, 95% confidence interval (CI) 1.03-1.14 per kg GWG, P = 0.003). Only half of the association of GWG on offspring adult BMI was mediated through birth weight and BMI up to 14 years of age.

CONCLUSION: Greater GWG is associated with an increased BMI in childhood through adulthood and with an increased risk of obesity in adults. Only part of the association with adult BMI is mediated by childhood BMI, suggesting that excessive GWG induces a persisting susceptibility to obesogenic environments. As GWG is greater in women with small pre-pregnancy body weight, this implies a reinforcement of the obesity epidemic in the next generation. Our findings provide support for avoiding excessive GWG.