Pregnancy weight gain among obese women. Obese women who gain more than 15 lbs. during pregnancy are more likely to retain some of the extra weight a year later, according to a study in the November 2009 issue of Obstetrics and Gynecology. Among 1,656 obese pregnant women, nearly 75% gained more than 15 pounds, the amount recommended by the Institute of Medicine. One year after giving birth, women were twice as likely to weigh 10 pounds more than their prepregnancy weight if they gained 15 to 25 lbs., compared with women who gained less than 15 lbs. The risk increased to four times as likely among women who gained more than 25 lbs. to 35 lbs. and eight times as likely among those who gained more than 35 lbs. About 50% of women in the United States are overweight or obese when they become pregnant, and obesity increases the risk of gestational diabetes and birth complications. "Given the serious morbidities associated with obesity and excessive weight gain, there is an urgent need for the development of interventions that successfully help women avoid excessive weight gain during pregnancy," the authors write.