To estimate whether exercise before the first cycle of in vitro fertilization (IVF) affects cycle outcomes.
A total of 2,232 patients were prospectively enrolled before undergoing their first cycle of IVF for the treatment of infertility from 1994–2003 at three IVF clinics in the greater Boston area. The primary IVF outcomes of interest included successful live birth and four points of cycle failure: cycle cancellation, failed fertilization, implantation failure, and pregnancy loss. Unconditional logistic regression adjusting for observed confounders was used to quantify the relation between self-reported exercise and cycle outcome.
In general, women who reported regular exercise were no more likely to have a live birth compared with those women who did not report exercise (odds ratio [OR] 0.8, 95% confidence interval [CI] 0.7–1.0; P=.07). Women who reported exercising 4 hours or more per week for 1–9 years were 40% less likely to have a live birth (OR 0.6, CI 0.4–0.8) and were almost three times more likely to experience cycle cancellation (OR 2.8, CI 1.5–5.3) and twice as likely to have an implantation failure (OR 2.0, CI 1.4–3.1) or pregnancy loss (OR 2.0, CI 1.2–3.4) than women who did not report exercise. In general, women who participated in cardiovascular exercise had a 30% lower chance of successful live birth (OR 0.7, CI 0.6–0.9) than women who reported no exercise.
Regular exercise before in vitro fertilization may negatively affect outcomes, especially in women who exercised 4 or more hours per week for 1–9 years and those who participated in cardiovascular exercise.
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