Is Coffee Bad for Reproduction?
Adapted from "Impact of female daily coffee consumption on successful fertility treatment: a Danish cohort study" published in July 2019 issue of Fertility and Sterility.
Worldwide, around 2 billion cups of coffee are consumed every day. Finland has the highest intake worldwide, with Denmark being the fourth most coffee-consuming country, with an average intake of 3 to 4 cups per day per adult. Coffee is commonly consumed by women who are attempting to conceive and by pregnant women.
The association between coffee or total caffeine intake and one’s fertility potential has been studied extensively among couples with natural fertility. Overall the findings have been inconsistent, although most recent studies indicate no effect.
However, a possible association between coffee or caffeine intake and treatment outcomes among couples undergoing Intrauterine Insemination (IUI), In Vitro Fertilization (IVF) treatments, or Frozen Embryo Transfer (FET) is less well studied.
The Danish study followed 1,708 couples presenting to the Aarhus University Hospital for infertility treatment and related the woman's pretreatment coffee consumption to the outcomes of IUI, IVF, or FET.
The study had several key advantages: A large sample size, the assessment of coffee intake preceding fertility treatment, and being conducting in Denmark, where coffee consumption is higher than in North America and where many pregnant women and women planning to conceive continue drinking coffee. This is in sharp contrast to North America, where the default professional recommendations and cultural expectations are the opposite.
Women reporting a daily coffee consumption had a 50% higher chance of achieving a live birth during IUI treatment cycles compared with the coffee abstainers. There was no association between daily coffee consumption (or the lack of it) and the outcome of IVF treatment.
So, where does this study leave us? First, it provides additional evidence that coffee may not be deleterious to fertility. The findings among women undergoing IUI, however, pose an intriguing question. Is it possible that coffee consumption might actually be good for fertility? Answering this question will require further research.
Official recommendations for women desiring to conceive and pregnant women are based on the precautionary principle. The World Health Organization recommends a daily caffeine intake below 300 mg. Yet findings from the present study did not indicate negative effects on the ability to conceive and carry a pregnancy to term.
A recent meta-analysis found a small, yet statistically significant increased risk of experiencing a spontaneous abortion after consumption of just 100 mg caffeine, corresponding to one cup of coffee. Thus, given the current knowledge, official recommendations could be separated and modified for those trying to conceive and for pregnant women.