Exercise in pregnancy: effect on fitness and obstetric outcomes-a randomized trial.

Abstract

A prospective randomized controlled trial was designed to assess the benefits and possible risks of aerobic exercise during pregnancy, using a fitness regimen based on the 2002 American College of Obstetricians and Gynecologists guidelines for exercise during pregnancy. Inactive women were randomized at 12-14 wk gestation to a group that remained sedentary or to a group that performed moderate aerobic exercise 45-60 min, 4 d·wk, through 36 wk gestation. Thirty-one subjects in each group completed the study. Compared with women who remained sedentary, active women improved aerobic fitness (P < 0.05) and muscular strength (P < 0.01), delivered comparable size infants with significantly fewer cesarean deliveries (P < 0.01), and recovered faster postpartum (P < 0.05), at least related to the lower incidence of cesarean section. Active women developed no gestational hypertension (P = 0.16 compared with controls) and reported no injuries related to the exercise regimen. In the active group, there was one premature birth at 33 wk by a woman with a history of premature delivery of twins at 34 wk. There were no differences between groups in the incidence of gestational diabetes, musculoskeletal pains during pregnancy, flexibility on sit-and-reach test, mean length of pregnancy, neonatal Apgar scores, placenta weights, overall length of labor, weight gain during pregnancy, or weight retention postpartum. Previously sedentary women who began exercising at 12-14 wk improved fitness and delivery outcomes.