A prospective study of the association between vigorous physical activity during pregnancy and length of gestation and birthweight.

Journal Article (Journal Article)


Current US pregnancy-related physical activity recommendations do not provide specific guidance for vigorous intensity activity. We examined the associations between vigorous physical activity during pregnancy and length of gestation and birthweight.


Women were recruited before 10 weeks gestation. At 13-16 weeks gestation, participants reported the type, frequency, and duration of their typical weekly vigorous physical activities. Activity domains included recreational, occupational, household, and child/adult care. Infant birth date was obtained from medical or vital records; if unavailable, self-report was used. Birthweight (from vital records) was studied among term births. We analyzed gestational age among 1,647 births using discrete-time survival analysis. We used logistic and linear regression to analyze preterm birth (birth at <37 weeks) and birthweight, respectively. Vigorous recreational activity was associated with longer gestation (any vs. none, hazard ratio (HR) [95% CI]: 0.85 [0.70, 1.05]) and we did not detect any dose-response association. Higher frequency of vigorous recreational activity sessions (adjusted for total volume of activity) was associated with a decreased odds of preterm birth (≥ 4 sessions/week vs. 0 or 1, OR [95% CI]: 0.08 (0.006, 1.0). Birthweight was not associated with physical activity measures. In summary, vigorous physical activity does not appear to be detrimental to the timing of birth or birthweight. Our data support a reduced risk of preterm birth with vigorous recreational activity, particularly with increased frequency of recreational activity sessions. Future studies should investigate the components of physical activity (i.e., intensity, duration, and frequency) in relation to birth outcomes.

Full Text

Duke Authors

Cited Authors

  • Jukic, AMZ; Evenson, KR; Daniels, JL; Herring, AH; Wilcox, AJ; Hartmann, KE

Published Date

  • July 2012

Published In

Volume / Issue

  • 16 / 5

Start / End Page

  • 1031 - 1044

PubMed ID

  • 21674218

Pubmed Central ID

  • PMC3386423

Electronic International Standard Serial Number (EISSN)

  • 1573-6628

International Standard Serial Number (ISSN)

  • 1092-7875

Digital Object Identifier (DOI)

  • 10.1007/s10995-011-0831-8


  • eng