(NaturalNews) Women with poor fertility may further harm their chances of conceiving if they drink more than four cups of coffee per day, according to a study conducted by researchers from Radboud University in Nijmegan, the Netherlands, and presented at the European Society for Human Reproduction and Embryology conference in Barcelona.
Researchers gave lifestyle questionnaires to all 9000 women who had undergone unsuccessful in vitro fertilization treatment in the Netherlands between 1985 and 1995. Approximately 16 percent of the women later became pregnant through natural means, 45 percent of them within six months of their last treatment. Women who drank more than four cups of coffee each day had 26 percent lower chance of conceiving that women who drank less.
Women who drank alcohol three times a week or more had a similarly reduced chance of conception, while being an overweight person who smokes more than one cigarette per day hampered fertility even more.
A 36-year-old overweight woman who smoked and who drank large amounts of coffee and alcohol would have only one-third the chance of conceiving as a woman of normal weight who had none of those unhealthy behaviors, the researchers calculated.
"We have to remind our patients that they may influence their chance of spontaneous pregnancy after IVF with a healthy lifestyle," lead researcher Bea Linsten said.
Fertility expert Bill Leger of the University of Sheffield, speculated that caffeine might lower fertility by having a mildly toxic effect on sperm and egg cells. In a woman with no fertility problems, the effects might be too small to be noticeable, but "if you're already subfertile it could push you over the edge," he said.
Fiona Ford of the Center for Pregnancy Nutrition agreed that the findings might not apply to women without fertility problems.
"Whilst the results of this study are interesting, there are evidently limitations to these findings," she said, "as post in vitro fertilization patients are a selective group who have already experienced problems with conception."