Caffeine Consumption Raises Miscarriage Rate: Study

A new study found more miscarriages for women who drank two cups of joe a day.

ByABC News
January 19, 2008, 4:26 PM

Jan. 21, 2008 — -- Expectant mothers have been confused for years about whether drinking that morning cup of joe could do harm to their unborn child.

Some previous studies have shown that consuming caffeine during pregnancy increases a woman's risk for miscarriage, while others have found that drinking just a couple cups of coffee a day doesn't pose much of a threat.

The latest research to examine the risk of caffeine consumption during pregnancy reveals that women who said they drank more than two cups of coffee per day had nearly double the risk of miscarriage compared with women who consumed no caffeine.

Researchers at the Kaiser Permanente Research Division in Oakland, Calif., followed 1,063 women during their pregnancy and asked about their caffeine intake. From October 1996 to October 1998, researchers examined the effects of the stimulant among the women who said they never decreased their caffeine consumption during their pregnancy.

They found that women who consumed 200 milligrams or more of caffeine daily the equivalent of two or more cups of coffee or five 12-ounce cans of soda had twice the risk for miscarriage. Moreover, the study found that even those women who consumed less than 200 milligrams of caffeine daily had about 40 percent increased risk for miscarriage.

"I am not at all surprised by this study," said Dr. Sherman Silber, director of the Infertility Center at St. Lukes Hospital in St. Louis. "Coffee is toxic stuff."

But does this study carry enough weight to finally answer the question of whether pregnant women should give up caffeine altogether?

Dr. De-Kun Li, primary study investigator, said that he hopes the research will convince doctors to tell their pregnant patients to avoid coffee completely.

"This is something you can control if you're worried about a miscarriage," Li said. "There's lots of things we can't control, but this is one thing that you can."

However, Li admitted that the study fails to answer the question of whether small amounts of caffeine significantly increase a woman's chance for miscarriage.