Effects of Caffeine Consumption by Women and Men on the Outcome of Fertilization.

Objective: The objective of this study was to estimate the association between caffeine consumption and fertilization (IVF) outcomes.

Methods: A total of 2474 couples were prospectively enrolled prior to undergoing their first cycle of IVF, contributing a total of 4716 IVF cycles. Discrete survival analysis adjusting for observed confounders was applied to quantify the relation between caffeine consumption and livebirth. Secondary outcomes of interest were oocyte retrieval, peak estradiol level, implantation rate, and fertilization rate.

Results: Overall, caffeine consumption by women was not significantly associated with livebirth (=0.74). Compared with women who do not drink caffeine, the likelihood of livebirth was not significantly different for women who drank low (>0-800 mg/week; odds ratio [OR]=1.00, 95% confidence interval [CI])=0.83-1.21), moderate (>800-1400 mg/week; OR=0.89, 95% CI=0.71-1.12), or high levels of caffeine (>1400 mg/week; OR=1.07, 95% CI=0.85-1.34). Greater caffeine intake by women was associated with a significantly lower peak estradiol level (=0.03), but was not associated with the number of oocytes retrieved (=0.75), fertilization rate (=0.10), or implantation rate (=0.23). There was no significant association between caffeine intake by men and livebirth (=0.27), fertilization (=0.72), or implantation (=0.24). The individual effects of consumption of coffee, tea, or soda by women or men were not related to livebirth.

Conclusion: Caffeine consumption by women or men was not associated with IVF outcomes.