TitleExposure analysis methods impact associations between maternal physical activity and cesarean delivery.
Publication TypeJournal Article
Year of Publication2015
AuthorsBovbjerg, ML, Siega-Riz, AMaria, Evenson, KR, Goodnight, W
JournalJ Phys Act Health
Volume12
Issue1
Pagination37-47
Date Published2015 Jan
ISSN1543-5474
KeywordsAdult, Cesarean Section, Cohort Studies, Data Collection, Exercise, Female, Gestational Age, Humans, North Carolina, Pregnancy, Prospective Studies, Research Design
Abstract
 

BACKGROUND: Previous studies report conflicting results regarding a possible association between maternal physical activity (PA) and cesarean delivery.

METHODS: Seven-day PA recalls were collected by telephone from pregnant women (n = 1205) from North Carolina, without prior cesarean, during 2 time windows: 17 to 22 weeks and 27 to 30 weeks completed gestation. PA was treated as a continuous, nonlinear variable in binomial regressions (log-link function); models controlled for primiparity, maternal contraindications to exercise, preeclampsia, pregravid 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 to 22 weeks followed an inverse J-shape, but at 27 to 30 weeks the curves reversed and were J-shaped. However, only (total) PA at 27 to 30 weeks was strongly associated with cesarean risk; this association was attenuated when women reporting large volumes of PA (> 97.5 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 nonlinear and dependent on gestational age at time of exposure, limiting the accuracy of analyses that collapse maternal PA into categories.

DOI10.1123/jpah.2012-0498
Alternate JournalJ Phys Act Health
PubMed ID24509873
PubMed Central IDPMC4590730
Grant ListM01 RR000046 / RR / NCRR NIH HHS / United States
T32 HD052468 / HD / NICHD NIH HHS / United States
CA109804-01 / CA / NCI NIH HHS / United States
R01 CA109804 / CA / NCI NIH HHS / United States
DK061981-05 / DK / NIDDK NIH HHS / United States
HD052468-01A2 / HD / NICHD NIH HHS / United States
R01 DK061981 / DK / NIDDK NIH HHS / United States
HD37584 / HD / NICHD NIH HHS / United States
R01 HD037584 / HD / NICHD NIH HHS / United States
P2C HD050924 / HD / NICHD NIH HHS / United States
RR00046 / RR / NCRR NIH HHS / United States