Current US guidelines suggest women with low body mass indexes should gain up to 40 pounds during pregnancy, women with normal BMIs should gain 25 to 35 pounds, and most obese women should gain about 15 pounds.
In 2003, about 25% of pregnant women in the U.S. gained more than 40 pounds during pregnancy, compared with 20% in 1990.
According to the US health charity, March of Dimes, women who gain too much weight during pregnancy have an increased risk of complications, including birth defects, problems during labor and delivery, foetal death and large infants.
A study published in the April issue of the American Journal of Obstetrics and Gynecology, analyzed 1,044 pairs of mothers and their 3 year old children and compared how much weight the mother had gained during pregnancy and the BMI of their children. The study found that women with excessive or adequate weight gain were about four times more likely than women with inadequate weight gain to have a child who was overweight by age three.
Experts said that women should follow current IOM guidelines until new guidelines are announced.