Caffeine and Fertility

Caffeine and Fertility: Female

Caffeine use is associated with a decreased potential to produce a pregnancy. Studies show link between caffeine and infertility .

In a 1999 study of 100 women who abstained consumed less than one cup of coffee or its equivalent per day conceived 26.9 pregnancies per 100 menstrual cycles compared with 10.5 per 100 menstrual cycles among those who consumed more than one cup of coffee per day.

In another study from 1989, 104 healthy women who had been attempting to become pregnant for three months were interviewed about their use of caffeinated beverages. In their subsequent cycles, women who consumed more than the equivalent of one cup of coffee per day were half as likely to become pregnant, per cycle, as women who drank less. The more a woman drank, the lower her chances for becoming pregnant.

The effects of caffeine intake from different sources on fertility were assessed in a national survey of 423 Danish couples. Couples were recruited to the study in 1992-95 through a mailing to 52,255 female trade union members seeking women who were 20-35 years old, lived with a partner, had no previous pregnancies, and intended to discontinue contraception in order to become pregnant. Compared with women with a very small caffeine intake, those with a moderate intake of caffeine had a lower chance for conception while those with a higher consumption had a much lower chance for pregnancy. The relationship held up after adjustments for weight, alcohol intake, diseases of the female reproductive organs, semen quality, and duration of the menstrual cycle.

In early 2005, a study published in the journal Diabetes Care demonstrated that caffeine makes it more difficult for insulin to control blood sugar. This problem, known as insulin resistance , can play an important role in women. Insulin resistance can cause a woman not to ovulate. Women who already have insulin resistance include those who are obese and those with a problem called PCOS.

Caffeine and Fertility: Male

Much confusion has arisen over caffeine use in males. When sperm are treated under laboratory conditions with caffeine there is a short increase in the percent of motile sperm. However, over the longer term, the percent of moving sperm declines more quickly.

When men drink caffeine, most studies show a decrease in their ability to produce a pregnancy. The same Danish study that found a decrease in fertility from caffeine in women also found a similar decrease when men were the ones consuming caffeine.