Caffeine doubles miscarriage risk.
January 21, 2008 04:46pm
Article from: Reuters
They said the study provided strong evidence that high doses of caffeine during pregnancy – 200mg or more a day or the equivalent of two cups of coffee – significantly increased the risk of miscarriage.
And they said the research might finally put to rest conflicting reports about the link between caffeine consumption and miscarriage.
“Women who are pregnant or are actively seeking to become pregnant should stop drinking coffee for three months or hopefully throughout pregnancy,” said Dr De-Kun Li of Kaiser Permanente Division of Research, whose study appears in the American Journal of Obstetrics and Gynaecology.
“There has been a lot of uncertainty about this,” Dr Li said.
“There was no firm advice from professional societies to say what a pregnant woman should do about caffeine intake.”
Dr Li said anywhere from 15 to 18 studies had found a link between caffeine use during pregnancy and miscarriage.
But that association had been clouded by the fact that many pregnant women avoided caffeine because it made them feel sick, which could skew the results.
Dr Li and colleagues took pains to control for that possibility. Their study involved 1063 pregnant women who were members of the Kaiser Permanente health plan in San Francisco from October 1996 through October 1998. Women in the group never changed their caffeine consumption during pregnancy.
What they found was women who consumed the equivalent of two or more cups of regular coffee or five 340ml cans of caffeinated soft drink – were twice as likely to miscarry as pregnant women who avoided caffeine.
This risk appeared to be related to the caffeine, rather than other chemicals in coffee, because they also saw an increased risk when the caffeine was consumed in soft drink, tea, and hot chocolate.
Dr Li said many researchers thought caffeine was harmful because it stressed the fetus’s immature metabolism. It may also decrease blood flow in the placenta, which could harm the fetus.
“To me, the safe dose is zero,” Dr Li said.
“If you really have to drink coffee, try to limit it to one cup or at the most two cups.”
Or better yet, switch to decaffeinated beverages, he said.