Large Study Shows Possibility of Safe Weight Loss during Pregnancy

A new study, published in the Journal of Obstetrics & Gynecology, found that some obese women may be able to safely lose some weight during pregnancy.

The study was conducted by Dr. Marie Blomberg from the University of Linkoping in Sweden. She looked at the medical records for more than 46,000 obese pregnant women who gave birth between 1993 and 2008 and divided the women into three categories of obesity: class 1 obesity (BMI between 30 and 35), class 2 (BMI between 35 and 40) and class 3 (BMI of 40 or higher). She found that those who gained less than current recommendation for obese pregnant woman (11-20 pounds) or even lost weight,  were less likely to deliver a large baby or need a Cesarean section than those who gained the recommended amount.

Some of the key findings included:

• Among women with class 2 obesity, only 17 percent of those who lost weight during pregnancy had a C-section, versus 24 percent of those who gained the recommended amount.
• Babies born to very obese women who lost weight seemed to do as well as babies with mothers that gained the recommended amount.
• Babies born to very obese women who lost weight were no more likely to go into fetal distress or have a low Apgar score — a measure of breathing, heart rate and other health indicators right after birth.

Dr. Blomberg concluded that the bottom line is that some weight loss may be “reasonably safe” for women who are severely obese. However, she cautioned women against starting any kind of weight-loss diet during pregnancy. Instead they should aim to eat a balanced, healthy diet and get regular moderate exercise, like a half-hour of walking each day.

We spoke with Dr. RoseMarie Jones, Medical Director of the bariatric program at the Community Hospital (North) of Indiana, about the study. She told us: “This very large study from Sweden adds important evidence for weight gain recommendations for obese women during pregnancy.  It is important for patients and physicians to know that women with severe obesity can safely gain less than the normal recommended amounts, or even lose weight during pregnancy.” Dr. Jones added that all pregnant women should, of course, consult with their own physician about their diet and exercise program.

MedLine’s full summary of this study is here.