Maternal weight tied to child's body composition

By Megan Rauscher

NEW YORK (Reuters Health) - Investigators have found that children, whose mothers had a larger body mass index (BMI) prior to pregnancy or a large mid-upper arm circumference in late pregnancy, also had higher levels of body fat at the age of 9 years than other children of the same age.

The amount of weight mothers put on during pregnancy, however, had no effect on their child's body fat.

Both BMI, the ratio between height and weight often used to determine whether or not a person is overweight or underweight, and mid-upper arm circumference are indicators of nutritional status. The findings suggest that maternal weigh rather than nutrition during pregnancy may be the factor with the greater effect on a child's predisposition to gain excess body fat.

However, "it is also possible that our results might be due to genetic factors transmitted from mother to child," Dr. Catherine R. Gale, of the University of Southampton, UK, told Reuters Health.

While evidence suggests that babies' fat mass at birth is greater if their mothers were overweight during pregnancy, it's less clear if this association persists into childhood.

To investigate, the UK team studied 216 nine-year-old children whose mothers had participated in a study of nutrition in pregnancy.

In analyses adjusted for the influence of age, birthweight, infant weight gain, duration of breast-feeding, maternal height, smoking and amount of weight gained during pregnancy, a larger maternal mid-upper arm circumference in late pregnancy and a higher pre-pregnancy BMI remained independent predictors of greater BMI at age 9 years in both boys and girls.

As maternal mid-upper arm circumference increased in late pregnancy, an equivalent increase in fat mass was observed in boys and girls