Coffee in moderation won't boost miscarriage risk

NEW YORK (Reuters Health) - Drinking moderate amounts of coffee during pregnancy won't increase a woman's likelihood of miscarrying, new research shows.

"Based on what we've seen, it's not a cause for great concern," Dr. David A. Savitz of Mount Sinai School of Medicine in New York City, the study's first author, told Reuters Health, noting that past research has had similarly "reassuring" results.

But because women in the study consumed a relatively small amount of caffeine -- the equivalent of less than two cups of coffee daily in early pregnancy and less later on -- the study can't answer the question of whether consuming more might be harmful, he said.

Savitz's study is unique in that some women reported their caffeine consumption before pregnancy, others reported it within the first 8 to 12 weeks, he noted. "There's an advantage in asking very early, when people can recall more accurately."

He and his team followed 2,407 pregnant women, 258 of whom miscarried. All of the women reported their caffeine consumption before they became pregnant; 4 weeks after their last menstrual period; and at the time of the interview.

Most women in the study who drank coffee or other caffeinated beverages consumed about 350 milligrams of caffeine daily before they became pregnant and in very early pregnancy, equivalent to 1.7 7-ounce cups of brewed coffee a day. At the time of the interview, their average caffeine intake had fallen to 200 milligrams.

At each of the three time points assessed, there was no statistically significant relationship between the amount of caffeine a woman consumed and her risk of miscarriage.

"These data provide evidence to suggest that, within the lower range examined, caffeine intake is not associated with risk of miscarriage," Savitz and his colleagues conclude.

SOURCE: Epidemiology, January 2008.