Maternal leisure-time exercise and timely delivery

Am J Public Health. 1998 Oct;88(10):1528-33. doi: 10.2105/ajph.88.10.1528.


Objectives: This study investigated whether, in a general obstetric population, exercise in pregnancy affects the timeliness of delivery. The hypothesis was that maternal exercise would not raise the risk of preterm birth.

Methods: A community cohort of 557 prenatal patients was followed up until the time of delivery. Data were collected on exercise in each trimester: none, low-moderate (< 1000 kcal [4184 kJ]/wk in energy expenditure), or heavy (> or = 1000 kcal/wk). Timely delivery was adopted as an outcome criterion. Thus, in the analysis, a term birth was treated as optimal and survival techniques were used to estimate risks for both preterm and postdates delivery.

Results: No association was found between low-moderate exercise and gestational length. Heavier exercise appeared to reduce, rather than raise, the risk of preterm birth. The adjusted relative risk among conditioned heavy exercisers was 0.11 (95% confidence interval = 0.02, 0.81). After term, conditioned heavy exercisers delivered faster than nonexercisers.

Conclusions: The most important finding was the lack of evidence that vigorous maternal exercise is a risk factor for preterm delivery. A promising finding was that conditioned heavy exercisers have timely deliveries.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Cohort Studies
  • Delivery, Obstetric*
  • Educational Status
  • Energy Metabolism
  • Exercise*
  • Female
  • Humans
  • New York
  • Pennsylvania
  • Pregnancy
  • Pregnancy Outcome*
  • Proportional Hazards Models
  • Risk Factors
  • Smoking
  • Time Factors