A prospective study of the effects of female and male caffeine consumption on the reproductive endpoints of IVF and gamete intra-Fallopian transfer

Background: This study evaluated the timing and amount of caffeine intake by women and men undergoing IVF and gamete intra-Fallopian transfer (GIFT) on oocyte retrieval, sperm parameters, fertilization, multiple gestations, miscarriage, and live births. Methods: A prospective study of 221 couples was conducted in Southern California between 1993 and 1998. 'Usual' caffeine intake during lifetime and 1 year prior to attempt, caffeine intake during the week of the initial clinic visit, as well as intake during the week of the procedure, was evaluated from beverages (coffee, soda, tea) and chocolates. Results: Not achieving a live birth was significantly associated with 'usual' female caffeine consumption [adjusted odds ratios (95% confidence intervals): 3.1 (1.1, 9.7) and 3.9 (1.3, 11.6) for intake of >2-50 and 50 mg/day, compared with 0-2 mg/day] and consumption during the week of the initial visit [2.9 (1.1, 7.5) and 3.8 (1.4, 10.7)] female compared with 0-2 mg/day, although caffeine use was low. Infant gestational age decreased by 3.8 (-6.9, -0.7) or 3.5 (-6.7, -0.3) weeks for women who consumed >50 mg/day of caffeine 'usually' or during the week of the initial visit. The odds of having multiple gestations increased by 2.2 (1.1, 4.4) and 3.0 (1.2, 7.4) for men who increased their 'usual' intake or intake during the week of the initial visit by an extra 100 mg/day. Caffeine intake was not significantly associated with other outcomes. Conclusions: This is the first IVF/GIFT study to report any effect of caffeine on live births, gestational age, and multiple gestations. If these findings are replicated, caffeine use should be minimized prior to and while undergoing IVF/GIFT.