The influence of long-term caffeine intake on pregnancy rate evaluated using human follicular fluid hormones and in vitro fertilization in mice

Abstract

OBJECTIVE: We evaluated the effect of habitual caffeine intake on in vitro fertilization (IVF) and embryo growth as well as its effect on follicular fluid (FF) and serum hormone levels following ovarian stimulation in infertile patients. Furthermore, in mice, we evaluated the fertilization rate and embryo growth by subjecting oocytes to continuous long periods of caffeine exposure. DESIGN: Comparison with follicular hormone level and caffeine intake in human and mice. MATERIALS AND METHODS: The human subjects (n = 68) were divided into four groups, and Group A, B, C and D were taken 0, 100, 200 and ≤ 300 mg caffeine/day, respectively. FF-estradiol (E2), progesterone (P4), total testosterone (T), inhibin B (InB), and androstenedione (An) levels were compared in the four groups in regard to oocyte quality, embryo quality, fertilization rate and pregnancy rate. For the mouse study, Three groups were given 0, 0.1, or 1 mg of caffeine daily. We evaluated the results of IVF among each group. RESULTS: 1) Human: The pregnancy rate decreased with increased caffeine intake: (A) 33.3%; (B) 20.0%; (C) 15.4%; and (D) 11.8%. It is noteworthy that T decreased in relation to caffeine intake: (A) 1,396 ng/dl; (B) 1,166 ng/dl; (C) 883 ng/dl; and (D) 673 ng/dl. T was significantly lower in the D group when compared to the A group (control) (P < 0.05). 2) Mice: The average number of oocyte per mouse given 1 mg caffeine/day was significantly lower, 17.7 than 39.0 in the control group (P < 0.05). The fertilization rate decreased, and blastocyst formation was significantly decreased depending on the amount of caffeine (64.0%, 49.8% and 38.2 %, respectively; P < 0.05). CONCLUSION: It is shown that a patient regularly drinks a significant amount of coffee, her FF- T and An are decreased; as a result, the likelihood of pregnancy following ART will be less. Mouse study indicated that caffeine intake has a negative affect on oocyte or embryo growth process.