Pregnant women who exercise can significantly lower their risk of giving birth to heavier babies, which has been associated with heavier weight into childhood and adulthood, and undergoing Caesarean sections, according to a meta-analysis published in the May issue of Obstetrics & Gynecology.


Senior author Margie Davenport, PhD, studied data on 5,322 pregnant women enrolled in 28 randomized controlled trials that compared standard care alone with standard care and supervised prenatal exercise. Supervision was defined as at least one exercise session performed with study personnel every two weeks throughout a given program. The analysis excluded any trials of interventions that involved only pelvic floor exercises, stretching, or relaxation.


The authors found that prenatal exercise reduced the odds of having a large newborn (birth weight greater than 4,000 g or greater than the 90th percentile for gestational age and sex) by 31% without affecting the risk of having a small newborn (birth weight less than 2,500 g or less than the 10th percentile for gestational age and sex) or gestational age at delivery. Prenatal exercise reduced the risk of having a Caesarean section by 20%. They also found that pregnant women who exercised gained less weight during their pregnancy and had lighter babies overall.