Citation
Bovbjerg, Marit L.; Siega-Riz, Anna Maria; Evenson, Kelly R.; & Goodnight, William (2015). Exposure Analysis Methods Impact Associations between Maternal Physical Activity and Cesarean Delivery. Journal of Physical Activity and Health, 12(1), 37-47. PMCID: PMC4590730Abstract
BACKGROUND: Previous studies report conflicting results regarding a possible association between maternal physical activity (PA) and cesarean delivery.METHODS: 7-day PA recalls were collected by telephone from n=1205 pregnant women from North Carolina, without prior cesarean, during two time windows: 17-22 weeks and 27-30 weeks completed gestation. PA was treated as a continuous, non-linear variable in binomial regressions (log-link function); models controlled for primiparity, maternal contraindications to exercise, pre-eclampsia, pre-gravid BMI, and percent poverty. We examined both total PA and moderate-to-vigorous PA (MVPA) at each time. Outcomes data came from medical records.
RESULTS: The dose-response curves between PA or MVPA and cesarean risk at 17-22 weeks followed an inverse J-shape, but at 27-30 weeks the curves reversed and were J-shaped. However, only (total) PA at 27-30 weeks was strongly associated with cesarean risk; this association was attenuated when women reporting large volumes of PA (>97.5th percentile) were excluded.
CONCLUSION: We did not find evidence of an association between physical activity and cesarean birth. We did, however, find evidence that associations between PA and risk of cesarean may be non-linear and dependent on gestational age at time of exposure, limiting the accuracy of analyses that collapse maternal PA into categories.
URL
http://dx.doi.org/10.1123/jpah.2012-0498Reference Type
Journal ArticleYear Published
2015Journal Title
Journal of Physical Activity and HealthAuthor(s)
Bovbjerg, Marit L.Siega-Riz, Anna Maria
Evenson, Kelly R.
Goodnight, William