Heavy moms-to-be who follow a regular workout regimen are more likely to stay within the recommended weight-gain guidelines, according to a study of 82 second-trimester women published in the BJOG: An International Journal of Obstetrics and Gynecology. And it's best to start exercising earlier in pregnancy rather than later.
This is especially notable after a recent review of 44 previous study published in the British Medical Journal found that dieting during pregnancy is safe for moms-to-be and does not carry any risks for the baby.
The researchers in BJOG study assigned one group of women to moderate, weekly exercise under supervision and to counseling on weight gain and home exercise. The others received standard prenatal care. Forty-seven percent of the exercisers gained more than the recommended weight during their entire pregnancy, which was still better than those who didn't exercise; 57 percent of them gained too much.
On average, the overweight women who exercised gained 22 pounds; the non-exercisers averaged 36 pounds. Blood pressure rates were similar in both groups, and so were the babies' health at birth, indicating that exercise was safe.
Being overweight before conceiving or gaining too much prenatal weight boosts the risks of birth defects, having an overly large baby, needing a Cesarean section and retaining pregnancy weight. Because it's harder to stick with a workout routine in the third trimester, and because exercise alone is not enough to lower risks associated with being overweight, experts recommend improving your diet and starting to exercise early in the first trimester. —Shari Roan