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Spring/Summer 2009 Vol. 9 Number 1

Table of Contents

Pregnancy Weight Gain

New Guidelines Balance Benefits and Risks

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How much weight should women gain during pregnancy? During the nearly 20 years since the Institute of Medicine last answered this question, research has added to our understanding of the effects of gestational weight gain on mothers and their children. Moreover, the percentage of American women who are overweight or obese has increased dramatically.

Nonetheless, the new guidelines issued by the IOM and National Research Council are similar to the 1990 set, though they are based on updated body mass index (BMI) categories and include a new recommended range of gain for women who start pregnancy obese.

Women at a normal BMI (18.5 to 24.9) should gain 25 to 35 pounds during pregnancy, the new guidelines state. Underweight women (BMI less than 18.5) should gain more, 28 to 40 pounds, and overweight women (BMI of 25 to 29.9) should gain less, 15 to 25 pounds. Where the 1990 report simply stated that obese women should gain at least 15 pounds, the new report says they should gain 11 to 20 pounds.

The latest review of the evidence focused not only on health outcomes for infants but also on the potential impact of weight gain on mothers. Evidence is consistent that some weight gain during gestation is necessary for fetal growth as well as breast, uterine, and placental growth. However, research also underscores women’s anecdotal experiences that it can be easy to gain weight during pregnancy and difficult to lose the extra weight after birth. The committee strove to balance the health needs of both infants and mothers in setting the new guidelines.

“That we came to such similar recommendations with a completely different approach should give women and their health care providers confidence that these recommendations are appropriate and useful,” noted Kathleen Rasmussen, a professor of nutrition at Cornell and chair of the committee that wrote the report.

The principal message: Women should start pregnancy at or as close to a normal BMI as possible and stay within the guidelines during pregnancy. Recognizing that this is easier said than done, the committee recommended support for programs and efforts to provide women counseling on nutrition and physical activity and opportunities to engage in healthy eating and exercise. Meeting all of the committee’s recommendations, however, will require major improvements in the health care offered to women before, during, and after pregnancy.  — Christine Stencel

 Weight Gain During Pregnancy: Re-examining the Guidelines. Committee to Re-examine IOM Pregnancy Weight Guidelines; Food and Nutrition Board, Institute of Medicine, and Board on Children, Youth, and Families, Institute of Medicine and National Research Council (2009, approx. 336 pp.; ISBN 0-309-13113-8; available from the National Academies Press, tel. 1-800-624-6242; $47.95 plus $4.50 shipping for single copies).

The committee was chaired by Kathleen Rasmussen, professor, division of nutritional sciences, Cornell University, Ithaca, N.Y. The study was funded by the U.S. Department of Health and Human Services’ Health Resources Services Administration, Centers for Disease Control and Prevention, National Institutes of Health (National Institute of Child Health and Development, National Institute of Diabetes and Digestive and Kidney Diseases, and Division of Nutrition Research Coordination), HHS Office of Women’s Health, and the HHS Office of Disease Prevention and Health Promotion; and the March of Dimes. Additional support was provided by the HHS Office of Minority Health (National Minority AIDS Council).

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Copyright 2009 by the National Academy of Sciences