Pre-pregnancy BMI is associated with offspring body composition in adulthood before adiposity-related disorders: a retrospective cohort.

Objective: To investigate the association between maternal pre-pregnancy BMI and offspring body composition in adulthood.

Design: Retrospective cohort. Undergraduates of nutrition or nutritionists were recruited at the baseline of the Nutritionists' Health Study between 2014 and 2017. Maternal pre-pregnancy BMI and current life aspects were self-reported through online questionnaires. Three body compartments were dual-energy x-ray absorptiometry-determined. The following variables were obtained: body fat (%), fat mass index (FMI) (kg/m2), android-to-gynoid fat ratio, visceral adipose tissue (VAT) (cm3), appendicular skeletal muscle mass index (ASMI) (kg/m2), total bone and femur mineral content (g) and density (g/cm2). Linear regression adjusted according to directed acyclic graphs recommendation was performed.

Setting: São Paulo, Brazil.

Participants: Healthy non-pregnant women (aged 20-45 years) (n 150).

Results: Median age and BMI were 22 years (IQR = 20, 29) and 22·3 kg/m2 (IQR = 20·4, 25·3), respectively. Pre-pregnancy BMI ≥ 25 kg/m2 was reported by 14·7 % of mothers. In fully adjusted models, maternal pre-pregnancy BMI was associated with their daughters' body fat % (β = 0·31; 95 % CI 0·0004, 0·63), FMI (β = 0·17; 95 % CI 0·03, 0·30), android-to-gynoid ratio (β = 0·01; 95 % CI 0·004, 0·02) and VAT (β = 0·09; 95 % CI 0·02, 0·16), but not with total bone density (β = 0·001; 95 % CI -0·003, 0·006) and content (β = 7·13; 95 % CI -4·19, 18·46). Direct association with ASMI was also detected, but lost statistical significance when participants whose mothers were underweight were excluded.

Conclusions: Maternal pre-pregnancy BMI was directly associated with offspring general and visceral adiposity but seems not to be associated with bone mass. Results reinforce importance of avoiding excess of maternal adiposity, as an attempt to break the vicious cycle of obesity transmission.