Pre-pregnancy weight linked with child's weight

The amount of body fat a child accumulates over time may be related to their mother's body mass index prior to and during pregnancy, study findings suggest.

"Obesity among mothers and children is a growing problem," Dr. Catharine R. Gale of Southampton General Hospital, UK, told Reuters Health.

The results of the research conducted by Gale and colleagues, shows that excess weight in the mother before and during pregnancy "may have a persisting and long-term influence on her child's tendency to fatness," Gale said.

The investigators analyzed body fat measurements for 216 mothers who participated in a nutrition study during pregnancy and 216 of their children during infancy and again at 9 years of age. Their findings are published in the Journal of Clinical Endocrinology and Metabolism.

They found that height-adjusted fat mass measurements among the children correlated with the mother's pre-pregnancy body weight and late-pregnancy upper arm circumference.

Mothers with lower body mass index - the ratio of height to weight often used to determine if an individual is under- or over-weight - prior to pregnancy and smaller arm circumference in late pregnancy had children with less body fat, Gale said.

"As the mother's body fat indicators increased so did those of her child," Gale told Reuters Health. "This association was present in both boys and girls, though the effect was greater in girls," she added.

For each one point increase in the mother's pre-pregnancy body mass index, their son's and daughter's fat mass index rose by 0.26 and 0.44 of a point, respectively.

However, while excessive weight gain during pregnancy has previously been linked to increased body fat in the child, this study identified no evidence of this association, the investigators note.

Further research is needed to determine if this association is from the effect of a mother's excess weight prior to pregnancy; the effect of a mother's lifestyle on that of her child; or a genetic factor passed from mother to child, Gale said.

SOURCE: The Journal of Clinical Endocrinology and Metabolism, October 2007.