Coffee impairs artificial insemination

More than four cups of coffee per day reduce the chances of success by 50 percent

Coffee Julius Schorzman / CC-by-sa 2.0
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Women who drink five or more cups of coffee a day have a 50 percent lower chance of getting pregnant through artificial insemination. Danish researchers have found this out in a study of around 4, 000 women. Accordingly, the rate of miscarriages increased by 40 percent, when the women drank particularly much of the caffeine-containing drink. The effects of excessive coffee consumption on pregnancy are comparable to those of smoking, the doctors warn, sharing their findings Tuesday at the annual meeting of the European Society of Reproductive Medicine (ESHRE) in Istanbul presented.

We were not surprised that coffee interferes with the pregnancy rate of artificial insemination. However, we were amazed at the scale of the impact, "says study author Ulrik Schioler Kesmodel from the Aarhus University Hospital in Denmark.

Earlier studies not clear

The influence of caffeine on women's fertility has been studied in numerous studies - but without meaningful results, as the researchers report: some found a negative effect on pregnancy, others did not. The recently published Danish study was carried out in a large special clinic for artificial insemination. A total of 3, 959 women who wanted to become pregnant either by fertilization in the test tube (IVF) or direct sperm injection into the egg cell (ICSI).

In the statistical analysis, the researchers also considered other factors such as the age of women, their Bodyma index, alcohol consumption or smoking habits. Independently of these, it was found that among the subjects who drank five or more cups of coffee a day, artificial insemination failed twice as often as those who consumed less. In general, an IVF succeeds in healthy couples in only about 20 out of 100 cases at the first attempt.

Up to four cups are allowed

Apart from the increased infertility, the rate of miscarriages increased by 40 percent, the researchers say. This is comparable to the effect that smoking has on the success of artificial insemination. However, in women who drank less than five cups a day, this did not affect pregnancy and pregnancy in any way. This fits the results of previous studies, in which researchers also identified four to six cups of coffee as a threshold, from which the coffee has an effect. display

In their presentation of their findings in Istanbul, the authors pointed out that their study provided measurable but not statistically unambiguous statements. However, it is another strong indication that coffee interferes with the success of artificial insemination. One does not want to worry those affected unnecessarily, "assures Kesmodel. But for women, based on their findings and previous studies, it is advisable not to drink more than four cups of coffee if they are undergoing IVF or ICSI. Whether the coffee enjoyment also affects natural pregnancies, the researchers have not investigated.

(Aarhus University Hospital, 04.07.2012 - IRE)