Maternal weight prior and during pregnancy and offspring's BMI and adiposity at 5-6 years in the EDEN mother-child cohort.

BACKGROUND: Beyond pre-pregnancy BMI, maternal weight change before and during pregnancy may also affect offspring adiposity.

OBJECTIVE: To investigate the relationship between maternal weight history before and during pregnancy with children's adiposity at 5-6 years.

METHODS: In 1069 mother-child dyads from the EDEN Cohort, we examined by linear regression the associations of children's BMI, fat mass and abdominal adiposity at 5-6 years with maternal pre-pregnancy BMI, pre-pregnancy average yearly weight change from age 20 and gestational weight gain. The shapes of relationships were investigated using splines and polynomial functions were tested.

RESULTS: Children's BMI and adiposity parameters were positively associated with maternal pre-pregnancy BMI, but these relationships were mainly seen in thin mothers, with no substantial variation for maternal BMI ranging from 22 to 35 kg/m2 . Gestational weight gain was positively associated with children's BMI Z-score, but again more so in thin mothers. We found no association with pre-pregnancy weight change.

CONCLUSIONS: Before the adiposity rebound, maternal pre-pregnancy thinness explains most of the relationship with children's BMI. The relationship may emerge at older ages in children of overweight and obese mothers, and this latency may be an obstacle to early prevention.