FRIDAY, July 20, 2001 (HealthDayNews) -- If you're pregnant and worried about what your favorite double espresso might do to your baby, a new study could put your fears to rest.
The research suggests that moderate caffeine intake during pregnancy doesn't harm a baby's development. However, previous studies have linked caffeine to delays in conceiving, low birth weight, premature delivery and miscarriage.
Those studies, particularly a pivotal animal study conducted by the U.S. Food and Drug Administration (FDA), led to an FDA recommendation in 1980 that pregnant women however much they love their lattes go cold turkey on caffeine while pregnant.
But as a coffee lover and a researcher in perinatal epidemiology at Yale University, Laura Grosso wanted to look into the caffeine conflict. She led a study that followed 2,714 women from the New Haven, Conn., area who gave birth between 1988 and 1991.
Her findings appear in a recent issue of the journal Epidemiology.
In the study, each woman provided details on how much coffee, tea and soda she drank during the first and third trimester of her pregnancy. Depending on how it's brewed, a cup of coffee can contain up to 100 milligrams of caffeine, while a cup of tea or a glass of cola contains about 40 milligrams.
After examining the data, Grosso's team reported that the consumption of moderate amounts of caffeine approximately 300 milligrams daily appeared to have no negative effects on fetal development. Only 7 percent of the women delivered a baby with impaired fetal growth.
Grosso found that during the first month of pregnancy, 38 percent of the women drank coffee, making it the primary source of caffeine consumption. Of the coffee lovers, 25 percent said they drank at least one cup daily. A quarter of the women drank tea, and 30 percent drank caffeinated sodas.
The average consumption of caffeine among the women in the study was 72.4 milligrams a day. But by the seventh month of pregnancy, that had dropped to an average of 54 milligrams a day.
Coffee was the drink of choice, with 35 percent of women drinking at least a cup every week and 21 percent drinking one cup or two cups per day.
"Most of the studies that have shown an association [between caffeine and effects on pregnancy], it was with much higher caffeine consumption," says Grosso. "It was more like 500 milligrams."
One of the limitations of her study, she notes, was that researchers had trouble finding a significant number of pregnant women who drank more than 300 milligrams of caffeine per day.
Grosso suspects media coverage of the impact of caffeine on pregnancy has made women more aware.
"There are not a lot of women consuming 500, 600 milligrams of caffeine per day," she says. "It's kind of a disappearing exposure."
Dr. Mark Klebanoff, director of the Epidemiology, Statistics and Prevention Research at the National Institute for Child Health & Human Development, says that fact does indeed make it more difficult to study the issue.
"Pregnant women just tend to lay off coffee, and even tea, to a much greater degree than they did 20, 30 or 40 years ago," he says.
He adds that the literature on caffeine and pregnancy is fairly inconclusive, and this study won't close the book on the debate.
However, he says, "if we've been looking at this pretty intensively for 20 years and still haven't really reached a clear and definite conclusion, it's certainly reasonable to think that caffeine isn't doing very much."
"It's certainly nowhere near as harmful in [terms of] making babies small as smoking is," he adds.
Grosso says based on her study and previous research, "I believe it is still prudent to tell women that they should not exceed more than 300 milligrams per day. That's probably, on average, maybe three mugs of coffee per day."
"It's probably OK to drink one to two cups per day," she adds.
What To Do
The National Institute for Child Health & Human Development's Center for the Evaluation of Risks to Human Reproduction has this review of caffeine and reproduction research.
The Coffee Science Source, created by the National Coffee Association, provides this Q&A on coffee and women's reproductive health. You can also check out this review from Chem-Tox.Com on coffee and caffeine during pregnancy.
