Previous physical activity may have impact upon success of in vitro fertilization
March 17, 2014
Women who are more physically active in the year before in vitro fertilization increase their chances to have a successful pregnancy, according to a study led by Kelly R. Evenson, PhD, research professor of epidemiology at the UNC Gillings School of Global Public Health.
Evenson and a team of co-researchers presented the findings in a paper published online Feb. 11 in Fertility and Sterility, the journal of the American Society of Reproductive Medicine.
Results derived from 121 women showed that lifestyles that included more active living — walking, bicycling, active transportation and less TV-watching — as well as sports and exercise, appeared to favor implantation and pregnancy.
Women with higher total activity measures for the previous year also were more likely to have favorable pregnancy outcomes. In addition, those with higher median active living and sports/exercise indices were more likely to have a clinical intrauterine gestation.
Among women who received in vitro fertilization, 51.2 percent resulted in implantation, 38.8 percent in clinical intrauterine gestation and 26.5 percent in live birth.
During 2010-2012, women receiving fresh or frozen embryo transfer after in vitro fertilization at the UNC Reproductive Endocrinology and Infertility Clinic were recruited by their physicians and enrolled after providing written informed consent. The women completed a questionnaire on past-year physical activity and wore a measuring device called an accelerometer from just after the embryo transfer to the first pregnancy test.
The odds of a positive pregnancy test and clinical intrauterine gestation were generally higher among those with higher active living, sports/exercise and total activity measures compared with those with lower scores indicating less physical activity in the past year.
From the time between embryo transfer and the first pregnancy test, more physical activity or less sedentary behavior, as measured by the accelerometers, appeared to have no impact on the success of implantation, intrauterine gestation or live birth. However, in general, the women were not very physically active.
Sedentary behavior comprises time spent in periods of little or no movement while awake, such as sitting or bed rest.
Evenson’s co-authors were Anne Z. Steiner, MD, MPH, assistant professor, and Katherine Calhoun, MD, of the UNC School of Medicine’s Department of Obstetrics and Gynecology; Amy H. Herring, PhD, professor, and David Pritchard, doctoral student, of the Gillings School’s biostatistics department; and Fang Wen, in the Gillings School’s epidemiology department.