(NaturalNews) Drinking as little as 10 ounces of coffee per day may double a pregnant woman's risk of miscarriage, according to a new study conducted by Kaiser Permanente researchers and published in theResearchers interviewed 1,063 pregnant women, including 102 who had already suffered a miscarriage, about their caffeine intake. The median length of pregnancy for the women at the time of interview was 71 days. Another 70 women miscarried before the end of their pregnancies, bringing the total to 172, or about 16 percent - a fairly normal miscarriage rate.Women who said that they never drank caffeine had a 12.5 percent chance of miscarriage, while women who reported drinking 200 milligrams or more of caffeine per day had a 24.5 percent miscarriage rate. This represented nearly twice the miscarriage risk of the non-caffeine drinkers. The effects of caffeine on miscarriage remained even after researchers adjusted for other risk factors, including age and smoking habits.Previously, some researchers have suggested that a connection between caffeine intake and miscarriage rate is illusory, and is caused instead by the fact that women who experience morning sickness tend to have healthier pregnancies due to hormonal changes in the body. Because women with morning sickness are less likely to drink caffeine, it then appears that reducing caffeine intake reduces miscarriage risk.But the current study found that the association between caffeine and miscarriage remained strong even after adjusting for different rates of morning sickness.Lead author De-Kun Li recommended that pregnant women give up caffeine for at least the first three to four months of pregnancy . "If, for whatever reason, they really can't do it, think of cutting to one cup or switching to decaf," Li said. "Stopping caffeine really doesn't have any downside."Two hundred milligrams of caffeine is approximately the amount found in 10 ounces of coffee or 25 ounces of tea.