A new report was published today by the Institute of Medicine (IOM) regarding weight gain of pregnant women. Not since 1990 have the guidelines regarding weight gain during pregnancy been reviewed. In the past 20 years, the demographics of pregnancy have evolved and as such, it is clearly time to rethink the information being provided to pregnant women and their caregivers.
There is now more diversity amongst pregnant women than there was in 1990, as well as more multiple births and pregnant women tend to be older than they used to be. The most daunting statistic is that more women today become pregnant while overweight or obese, and continue to gain weight, putting themselves at risk for chronic disease and increasing health risks for the baby.
“Women not only should be within a normal BMI range when they conceive, but also should gain within the ranges recommended in the new guidelines,” per the new IOM report.
A committee was formed at the IOM to re-examine the pregnancy weight guidelines, and focused on “factors that affect pregnancy begin before conception and continue through the first year after delivery.”
An agreement was made that “One of the most important modifiers of pregnancy weight gain and its impact on a mother’s and her baby’s health is a woman’s weight at the start of pregnancy.” The best measure of this is BMI, and the guidelines have been updated to match the World Health Organization (WHO) BMI categorizations.
The new IOM guidelines on pregnancy weight gain differ from the old in two significant ways:
- Now based on WHO BMI categorizations, rather than Metropolitan Life insurance tables.
- Offers specific, relatively narrow ranges of recommended weight gain for obese women.
The new guidelines suggest that a woman of normal weight (BMI range of 18.5-24.9) should have a total weight gain of 25-35 pounds during pregnancy with about one pound/week gained in the last two trimesters. For obese women, they should have a total weight gain of 11-20 pounds with about .5 pound/week gained in the last two trimesters.
Advisements for special circumstances include:
- Pregnant teens should follow adult BMI categorizations.
- Twin pregnancy weight gain should be for normal BMI 37-54 pounds, overweight 31-50 pounds and obese 25-42 pounds.
The IOM encourages that these weight gain guidelines be followed in conjunction with dietary and exercise recommendations provided by your physician or caregiver.
Learn your BMI now with our free BMI calculator.
See the full report at IOM.