This article is more than 5 years old. Information may no longer be current.
IOM released new guidelines for weight gain during pregnancy
Click Here to Manage Email Alerts
Overweight and obese women now have new pregnancy weight gain guidelines from the Institute of Medicine and National Research Council, the first update since 1990.
The new report reflects the changing demographics of American women, particularly the surge in the number who are overweight or obese. Research published after the 1990 IOM report demonstrated that a high proportion of women were either given no advice on weight gain or were advised to gain outside of their recommended range.
In the 19 years since the last report, “the concern about women’s health has increased substantially, in part because women are older when they’re getting pregnant, are having more multiples and are more racially and ethnically diverse. But most particularly, women today are a great deal heavier,” Kathleen M. Rasmussen, ScD, RD, chair of the Committee to Reexamine IOM Pregnancy Weight Guidelines, told Endocrine Today.
According to the report, healthy, normal-weight women (BMI 18.5-24.9) should gain 25 to 35 lb during pregnancy; overweight women (BMI 25-29.9) should gain 15 to 25 lb; and underweight women (BMI <18.5) should gain even more — 28 to 40 lb.
The report specifies a new range for obese women (BMI >30) that limits pregnancy weight gain to 11 to 20 lb. The recommendation is based primarily on data for women with BMI between 30 and 35 due to a lack of data on women with BMI >35, according to Rasmussen.
“For underweight and normal-weight women, the average weight gain during pregnancy is similar to the middle of the range for the guidelines in the report. But for overweight and obese women, there is a 10-lb gap. In other words, we are suggesting that the mean weight gain has to be quite a bit lower,” Rasmussen said.
The new recommendations are based on the World Health Organization BMI categories rather than the previous categories from the Metropolitan Life Insurance tables.
Although the report focuses on weight changes during pregnancy, the committee also noted that women’s weight at conception affects mothers and infants, too. To minimize the risks, women should aim to conceive while at a normal BMI and gain within the guidelines during pregnancy, the committee concluded. Noting that entering pregnancy with a normal BMI as well as gaining within the recommended levels during gestation are the best ways to minimize the risks, the report called for increased diet and exercise counseling and programs to help women attain a normal BMI.
“Since the last report was issued, we’ve had a number of observational studies tell us that women who gain within these guidelines do better than women who gain outside the guidelines — above or below. Because these guidelines are based on both the health of the mother and the health of the child, I think we can have a lot of confidence that these are reasonable targets for American women to be using,” Rasmussen said.
The effects of excess weight gain among expectant mothers include an increase in the risk for retaining extra weight after birth or requiring a cesarean section. The risks for children include being too small or too large at birth.
Each of these consequences increases the chance for later health problems for mothers and their children, according to the report.
The report also encourages health care professionals to increase counseling on weight, diet and exercise not just during pregnancy but well before women plan to conceive, given that many should lose weight to begin the pregnancy closer to or at a normal BMI. – by Katie Kalvaitis and Jennifer Southall
For information regarding the report, visit iom.edu/pregnancyweightgain.
The new IOM recommendation on weight gain during pregnancy comes at a time when the prevalence of overweight and obesity (based on BMI) are at their historical highest, with two-thirds of women of child-bearing age affected in the United States. While women who are normal weight tend to gain within the recommended limits, women who are overweight and obese gain excessive amounts of weight during pregnancy. Excess weight gain in pregnancy is associated with worse outcomes for both the mother and for the baby. Adverse maternal outcomes include unscheduled cesarean delivery and postpartum weight retention. Adverse outcomes for the infant include preterm birth, both small and large for gestational age babies and childhood obesity. The new IOM guidelines recognize the importance of optimizing maternal weight preconception. They emphasize the importance of preconception counseling to improve the quality of diet and increase the frequency and duration of physical activity to achieve weight loss. Nutrition counseling should continue into the postpartum period to prevent weight retention and achieve long-term weight loss goals. The rising prevalence of overweight and obesity correlates with a rising prevalence of diabetes. Addressing overweight and obesity in women of child-bearing age will go a long way to reducing future risk for diabetes and its complications in the U.S. population. It is important that primary care providers and obstetricians help their patients implement lifestyle changes to achieve normal BMI levels preconception, avoid excess weight gain during pregnancy and eliminate postpartum weight retention. State and federal governments will need to address the barriers to achieving normal BMI, such as lack of education, safe places for recreation and access to and affordability of healthy food.
– Florence M. Brown, MD
Co-Director of the Joslin-Beth Israel Deaconess Diabetes
in Pregnancy Program
and Assistant Professor at Harvard Medical School