Still, concerns about the health effects of coffee and other caffeinated beverages for pregnant women -- or those trying to conceive -- have been an issue for years. Some studies suggest too much caffeine can increase the risk of miscarriages, while others haven't found any link. And other research has associated caffeine intake with reduced fertility in women.
These studies are all about statistical links and associations made by surveying women about their coffee drinking habits. There's no way to definitively conclude that consuming more caffeine directly affects fertility and pregnancy since it's unethical to randomly assign a group of women to drink coffee just to see whether they will be harmed by it.
"The research is inconsistent, especially when it comes to what is the cut-off for consumption," says Dr. Alice Domar, an infertility specialist who heads the Domar Center for Mind/Body Health in Waltham.
She points to a 2003 study that found women whose caffeine intake was under 50 milligrams a day -- the amount in less than one cup of brewed coffee -- had higher pregnancy rates after undergoing in vitro fertilization compared with those with higher caffeine intakes who also had IVF.
"Infertility specialists tend to tell their patients to keep it to a cup or two [of coffee] a day," Domar says. "But I do advise my patients to try to keep to below 50 mg."
That pretty much means sticking with decaffeinated beverages if you're trying to get pregnant.
"We are doing research on this right now but don't have final data yet," Domar says. Stay tuned for an update.
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