Gestational weight gain and childhood body mass index across three generations: Results from the 1993 Pelotas (Brazil) Birth Cohort

Background Gestational weight gain (GWG) has been associated with the accumulation of body fat in offspring, but little is known about the intergenerational relationship. Objective To assess the effect of GWG in grandmothers and mothers on the child's body mass index (BMI). Methods This is a sub-study nested in the 1993 Pelotas (Brazil) Birth Cohort at 22 years follow-up visit. We calculated the BMI-for-age z-score (BAZ) and evaluated overweight (>2 SD in <= 5 years of age and >1 SD for >5 years of age for BAZ). Grandmothers' and mothers' GWG were calculated as the difference between weight in the beginning of pregnancy and the last recorded weight before delivery. We standardized the GWG by adjusting for pre-gestational BMI. We also categorized GWG as adequate, excessive, or insufficient, in accordance with the Institute of Medicine (2009). Linear and logistic regressions stratified by child's age (<= 2 years; 2.01-5 years; >5 years) were used. Structural equations were modelled to calculate the total, indirect, and direct effects of grandmothers' and mothers' GWG on children's BAZ. Results Nine hundred and forty-six out of 1113 children evaluated were 5 years of age or under. There was an indirect effect (through maternal birthweight, maternal pre-gestational BMI, maternal GWG, and child birthweight) of grandmother GWG on grandchild BAZ, from 2.01 to 5 years of age [beta = 0.12 95%CI: 0.04-0.20 (P < 0.01)]. Maternal GWG directly increased the child's BAZ at >5 years of age [beta = 0.34 95%CI: 0.15-0.53 (P < 0.001)]. Conclusions GWG's effect on BMI does seem to be transmitted across three generations. Managing this will require health education during the gestational period for women and their families.

Automated summary

The study found that gestational weight gain of grandmothers and mothers can impact the child's body mass index, suggesting that the effect of GWG may be transmitted across three generations. Therefore, health education during gestation for women and their families will be necessary to manage this issue.