Objective: To estimate whether exercise before the first cycle of in vitro fertilization (IVF) affects cycle outcomes.
Methods: 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.
Results: 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.
Conclusion: 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.
Level of evidence: II-2.