Relationship between maternal pre‐pregnancy body mass index, gestational weight gain and childhood fatness at 6–7 years by air displacement plethysmography

This study aims to investigate the effect of maternal pre‐pregnancy body mass index (BMI) and gestational weight gain (GWG) on offspring body composition. In this prospective cohort study, offspring body composition at 6 years of age was obtained through air displacement plethysmography. Linear regression was used to obtain crude and adjusted coefficients. Information regarding offspring body composition and maternal pre‐pregnancy BMI was available for 3156 children and on offspring body composition and GWG for 3129 children. There was a direct association of maternal pre‐pregnancy BMI and GWG with offspring's fat mass (FM), fat‐free mass (FFM), fat mass index (FMI), fat‐free mass index (FFMI) and body fat percent (BF%) in crude and adjusted analyses. After adjustment for co‐variables, for each kg m(−2) of maternal pre‐pregnancy BMI increase, there was a mean increment of 0.13 kg in the offspring FFM, 0.06 kg m(−2) in FFMI, 0.11 kg in FM, 0.07 kg m(−2) in FMI and 0.18% in BF%. For each kilogram of maternal GWG increase, there was a mean increment of 0.08 kg in offspring's FM, 0.05 kg m(−2) in FMI, 0.04 kg in FFM, 0.01 kg m(−2) in FFMI and 0.18 % in BF%. Mothers with a higher pre‐pregnancy BMI or GWG tend to have children with greater adiposity at age 6 years. Fetal overnutrition is more likely among mothers with greater BMI during pregnancy; as a consequence, it can accelerate the childhood obesity epidemic.