PHILADELPHIA, July 7 (UPI) -- Although women are often warned about the dangers of exercising while pregnant, a review of clinical trial data suggests exercise is safe for both mother and fetus.
Exercise during pregnancy does not increase the risk of pre-term birth and lowers the chance of a medically necessary cesarean section, researchers at Thomas Jefferson University found in the study.
Despite previous studies showing exercise does not pose health risks for women with high-risk pregnancies and that it can reduce complications during pregnancy, women continue to be scared away from all kinds of exercise while pregnant.
"The thinking was that exercise releases norepinephrine in the body, which is a chemical that can stimulate contractions of the uterus, and thus lead to preterm birth," Dr. Vincenzo Berghella, director of maternal fetal medicine at the Sidney Kimmel Medical College at Thomas Jefferson University, said in a press release. "But numerous studies including this new meta-analysis, have since shown that exercise does not harm the baby, and can have benefits for the mom and baby."
For the study, published in the American Journal of Obstetrics and Gynecology, researchers pooled data from nine previous studies, focusing on 1,022 women who exercised for 35 to 90 minutes 3 or 4 times a week during pregnancy, and 1,037 who did not. The worm were mainly normal weight with uncomplicated pregnancies.
Women who exercised were found to have similar rates of preterm birth, similar weights at birth and their babies were born at a similar gestational age as those who did not exercise.
Women who exercised gave birth vaginally 73 percent of the time and 17.9 percent of them had a c-section, compared to 67 percent for those who did not exercise giving birth vaginally and 22 percent required a c-section.
Women who did not exercise had higher incidence of gestational diabetes and hypertensive disorders when compared to those who exercised, suggesting worthwhile health benefits for women who exercise.
"There are many reasons women pull back on exercise during pregnancy -- discomfort, an increase in tiredness and feeling winded by low level exertion," Berghella said. "This paper reinforces that exercise is good for the mom and the baby and does not hold any increased risk preterm birth."