Pregnancy Weight Harder to Lose for Obese Women

We all know how important it is to be healthy while you are pregnant, but even more so for women who are obese. Given the high rate of obesity, new guidelines have been issued recommending that the heavier a woman is, the less weight she should gain during pregnancy.

In research that was made public today, Kaiser Permanente confirmed that women who are obese and gain more weight than they should during pregnancy are much more likely to keep the weight on after giving birth. Nearly three out of four women that participated in the study gained more than 15 pounds during pregnancy and, on average, these women retained 40 percent of the extra weight a full year after they gave birth.

Dr. Kimberly K. Vesco, M.D., said, “Younger women and first-time mothers were the most likely to gain too much weight. The extra weight increased the risk for complications like hypertension, diabetes, preeclampsia, C-sections, and birth injuries.”

Approximately half of the pregnant women in the United States today are either overweight or obese, which is up from about 25 percent four decades ago. Obesity is defined as having a body mass index (BMI) that is 30 or more, and for most women that means carrying at least 30 extra pounds for their size. Normal weight is considered to be a BMI of 18.5-24.9, and overweight is considered to be 25-29.9. For example, a woman that is 5-foot, 2-inches tall who weighs approximately 135 pounds would be considered at the upper limit of the normal range (BMI = 25), and at 165 pounds she would be considered overweight (BMI = 30). A woman that is 5-foot 7-inches tall would be considered normal weight up to 160 pounds (BMI = 25) and considered obese at 195 (BMI = 30).

A total of 1,656 women that had a BMI of 30 or over at the beginning of their pregnancies were enrolled in this newly published study. The women were then followed for up to 18 months after their delivery.

Some previous studies suggest that infants that are born to obese women, who don’t gain much weight during their pregnancy, will have fewer delivery complications and better outcomes than the infants that were born to women who gained more weight than is recommended. The Kaiser research team began recruitment for a study to examine whether very obese women and their infants fare better when they gain no weight at all during pregnancy.

Victor Stevens, Ph.D. and the Kaiser Permanente Center for Health Research senior investigator, said that the “Healthy Moms” study, which was funded by a $2.2 million dollar grant from the federal government, will include women that are between 50 to 100 pounds above their normal weight at the start of their pregnancy. He stated, “These are not women with just a few pounds to lose. These are women who are carrying so much extra weight that it is a risk to themselves and their baby.”

Half of the women who were recruited for the study will receive standard care, which includes a single counseling session that will discuss nutrition and diet. The other half of the women will receive more intensive counseling to help teach them strategies for healthy eating and they will be able to attend weekly support sessions designed to reinforce positive behaviors. Those women will also be give personalized eating plans that will restrict their calorie intake to about 2,000 a day. The main goal is for these women to be within 30 percent of their pre-pregnancy weight after they deliver.

Stevens said, “The new IOM guidelines call for gaining no more than 20 pounds, but for women who are very obese this may not be the best advice. We want to see if outcomes are better if these women gain no weight or even lose some weight.”