Impact of female daily coffee consumption on successful fertility treatment: a Danish cohort study.

OBJECTIVE: To investigate whether female coffee consumption affects the chance of achieving a clinical pregnancy and a live birth among women and couples receiving medically assisted reproduction (MAR) treatment.

DESIGN: Cohort study with prospectively collected exposure data.

SETTING: Public fertility clinic.

PATIENT(S): A total of 1,708 women and potential partners undergoing fertility treatment, contributing with 1,511 intrauterine insemination (IUI) cycles, 2,870 in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles, and 1,355 frozen embryo transfer cycles.

INTERVENTION(S): None.

MAIN OUTCOME MEASURE(S): Clinical pregnancy and live birth in consecutive treatment cycles in the Danish national health registries, enabling complete follow-up, and estimation of the cumulative chance of live birth for three consecutive treatment cycles.

RESULT(S): Among women receiving IVF or ICSI treatment, coffee consumption did not seem to affect the chance of achieving a clinical pregnancy and a live birth. Women treated with IUI who had a daily coffee consumption of 1-5 cups were more likely to achieve a clinical pregnancy (adjusted relative risk 1.49; 95% confidence interval, 1.05-2.11) and live birth (adjusted relative risk 1.53; 95% confidence interval, 1.06-2.21) compared with the reference group of coffee abstainers.

CONCLUSION(S): Women consuming 1-5 cups versus none had a 1.5-fold higher probability of achieving a pregnancy or a live birth when receiving IUI. No associations were found, however, between women's daily coffee consumption and achieving a pregnancy or a live birth from IVF/ICSI.