OAKLAND, Calif., April 15 2014 — Gaining both too much or too little weight during pregnancy appears to increase the risk of obesity in the child, according to a Kaiser Permanente study published today in the American Journal of Obstetrics and Gynecology.
The study is the largest to examine current Institute of Medicine recommendations regarding gestational weight gain in relation to childhood obesity.
“Exceeding the current Institute of Medicine recommendations was associated with a 46% increased risk of having an overweight or obese child between ages 2 and 5,” said Monique M. Hedderson, PhD, senior investigator of the study and research scientist with the Kaiser Permanente Division of Research in Oakland, Calif. “The association was stronger among normal weight women who gained both above and below these recommendations.”
The Institute of Medicine’s 1990 guidelines for gestational weight gain had no upper limit for overweight and obese women. In 2009, new guidelines were introduced based on a woman’s pre-pregnancy body mass index (BMI). For obese women (BMI of 30 or greater), the recommended weight gain during pregnancy is 11 to 20 pounds; for overweight women (BMI between 25 and 29) it is 15 to 25 pounds; for normal weight women (BMI between 18.5 and 25), it is 25 to 35 pounds; and for underweight women (BMI
Using Kaiser Permanente HealthConnect®, an electronic health records system, the researchers identified 4,145 racially diverse female members of Kaiser Permanente Northern California who had completed a health survey between 2007 and 2009 and subsequently delivered a single child. For their children, overweight/obesity was defined as a BMI between ages 2 and 5 that was greater than or equal to the 85th percentile of the Centers for Disease Control and Prevention (CDC) child growth standards.
Among women who gained above the Institute of Medicine recommendations, 20.4% of their children were overweight or obese, compared with 14.5% in women who met the recommendations and 19.5% in women who were below the recommendations.
After adjusting for confounding factors, the researchers found that all women who exceeded the Institute of Medicine recommendations were 46% more likely to have an overweight/obese child. Normal weight women with weight gainabove the Institute of Medicine recommendations were 79% more likely to have an overweight/obese child, and women whose weight gain was below the recommendations were 63% more likely.
The researchers said the results suggest that gestational weight gain during pregnancy could potentially have long-term impacts on the baby’s subsequent growth and weight.
“The stronger association we found among normal weight women who gained too much weight during pregnancy suggests that perhaps excess weight gain in pregnancy may have an impact on the child that is independent of genetic factors,” Hedderson said. “There might be some programming that’s occurring from the excess nutrients that the baby is getting.”
Sneha B. Sridhar, MPH, project coordinator at the Division of Research and the study’s lead author, said animal studies have shown that under- or over-nutrition during pregnancy can result in permanent changes that put the fetus at risk of becoming obese later in life.
“Gaining either too little or too much weight in pregnancy may permanently affect mechanisms that manage energy balance and metabolism in the offspring, such as appetite control and energy expenditure," Sridhar said.
The study highlights the need for lifestyle interventions to help women gain the right amount of weight during pregnancy, Hedderson said. For example, the Division of Research currently has a study underway called Gestational Lifestyle Optimal Wellness (GLOW), which is studying an intervention to help pregnant women who are overweight and obese to make healthier lifestyle choices.
“Gaining appropriate weight during pregnancy can reduce a lot of complications,” Hedderson said. “We need to do a better job of in counseling women about weight gain during pregnancy. It can be a hard thing to talk about.”
In addition to Hedderson and Sridhar, co-authors of the study were: Jeanne Darbinian, MPH, Samantha F. Ehrlich, PhD, Margot A. Markman, BA, Erica P. Gunderson, PhD, and Assiamira Ferrara, MD, PhD, all of the Kaiser Permanente Division of Research.
This research was supported by a grant from the Health Resources and Services Administration (R40MC21515).