Vigorous Exercise and Birth Outcomes in a Sample of Recreational Exercisers: A Prospective Study Across Pregnancy

• Published in: Obstetrical & gynecological survey Vol. 61; no. 11; pp. 699 - 701
• Main Authors: Duncombe, Diane, Skouteris, Helen, Wertheim, Eleanor H, Kelly, Leanne, Fraser, Virginia, Paxton, Susan J
• Format: Journal Article
• Language: English
• Published: Lippincott Williams & Wilkins, Inc 01-11-2006
• ISSN: 0029-7828; 1533-9866
• DOI: 10.1097/01.ogx.0000243902.53983.05

An estimated 10% of Australian women of childbearing age exercise vigorously on a regular basis. This prospective study sought to determine whether this practice is associated with low infant birth weight or low gestational age at birth. Participating in the study were 148 pregnant women whose exercise frequency and intensity were monitored at baseline; at 16 to 23, 24 to 31, and 32 to 38 weeks gestation; and 1 to 2 weeks postpartum. Two definitions of vigorous exercise were used, one formulated by Bell et al (at least 30 minutes of running, swimming, or other aerobic activity at no less than 50% of maximal heart rate) and the other based on American College of Obstetricians and Gynecologists (ACOG) recommendations (up to 15 minutes of exercise at a heart rate of 140 or less at least 3 times each week).More than 85% of women exercised vigorously according to the Bell criteria, and approximately 60% of exercising women exceeded the ACOG criteria. Neither birth weight nor gestational age at birth could be related to the level of exercise, regardless of which set of criteria for exercise intensity was applied. Exercise level could not be implicated in the delivery of 4 low-birth-weight infants.This prospective study yielded no evidence that the intensity, duration, and/or frequency of vigorous exercise performed by pregnant women are associated with significantly adverse pregnancy outcomes. The investigators point out, however, that no conclusions should be drawn before replicating these findings in a large and more diverse group of pregnant women.