A Prospective Study of the Association Between Vigorous Physical Activity During Pregnancy and Length of Gestation and Birthweight

Abstract

Summary Current U.S. pregnancy-related physical activity recommendations do not provide specific guidance for vigorous intensity activity. Our objective was to examine 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.

Physical activity in pregnancy and adverse birth outcomes

“…The findings are similar to those of a study in North Carolina from 2004 to 2007 23 , in which pregnant women responded to a questionnaire by telephone, providing information on their physical activity in various domains (leisure-time, job-related, housework, and child and adult care), with no association detected between high physical activity in the first trimester and LBW or PTB.…”

Linking Nontraditional Physical Activity and Preterm Delivery in Urban African-American Women

“…Leisure time physical activity (LTPA) may influence PTD, as several existing studies suggest a protective association among non-Hispanic Whites (Berkowitz, Kelsey, Holford, & Berkowitz, 1983; Domingues, Matijasevich, & Barros, 2009; Evenson, Savitz, & Huston, 2004; Jukic et al, 2012; Leiferman & Evenson, 2003; Savitz & Murnane, 2010); however, only two studies are focused on the African-American population (Misra, Strobino, Stashinko, Nagey, & Nanda, 1998; Orr, James, Garry, & Newton, 2006). Misra and colleagues (1998) in a cohort including low-income African Americans from the University of Maryland clinics from 1988 to 1989 (n = 1,172), reported decreased odds of PTD for women who participated in LTPA for 60 or fewer days during the first and second trimesters of pregnancy (combined; odds ratio [OR], 0.51; 95% CI, 0.27–0.95), and increased odds of PTD for women who climbed stairs 10 or more times per day (OR, 1.60; 95% CI, 1.05–2.46), and walked for a purpose 4 or more days per week (OR, 2.10; 95% CI, 1.38–3.20; Misra et al, 1998).…”

Exercise during pregnancy. A narrative review asking: what do we know?

“…It has traditionally been thought that exercise, especially high-intensity exercise, might lead to earlier parturition, mainly due to hormonal factors 12 98. However, several recent studies suggest that moderate-intensity exercise does not lead to earlier births in healthy pregnant women 36 99–101…”