New York - Pregnant women need no longer give up their morning cup of coffee.
A research review by The American College of Obstetricians and Gynaecologists had found that moderate caffeine consumption probably won't increase the risk of a miscarriage or premature birth.
Until recently, studies have had conflicting findings about the effect of moderate caffeine consumption on pregnancy complications but a College committee has reviewed the evidence.
"I think it's time to comfortably say that it's okay to have a cup of coffee during pregnancy," Dr. William Barth, the chair of the College committee, told Reuters Health.
The College's Committee on Obstetric Practice said that 200 milligrams of caffeine a day - about the amount in a 12-ounce cup of coffee - doesn't significantly contribute to miscarriages or premature births.
That definition of "moderate caffeine consumption" would also include drinking about four 8-ounce (about 226g) cups of tea or more than five 12-ounce cans of soda a day, or eating six or seven dark chocolate bars.
The committee said the evidence was not clear on whether consuming more than 200 mg of caffeine a day might increase pregnancy risks.
The group considered two recent studies, each of which followed more than 1 000 pregnant women.
One study, led by Dr. David Savitz of The Mount Sinai Medical Centre in New York, found no increased rate of miscarriage for women who consumed low, moderate, or high levels of caffeine at different points in their pregnancy. In the other, Dr. De-Kun Li and his colleagues at Kaiser Permanente's Division of Research in Oakland found a higher risk of miscarriage in women who consumed more than 200 mg of caffeine per day, but no extra risk at lower levels.
The committee also pointed to two other studies that found that a mother's moderate caffeine intake did not make it any more likely she would deliver a baby prematurely.
Research has shown that caffeine is able to cross the placenta, which led to worries that it could cause miscarriage or premature birth.
In the United States, about 16 percent of all pregnancies end in miscarriage and about 12 percent of babies are born prematurely.
Barth said previous studies were mixed and unclear about the link between caffeine and pregnancy risks. It was the new findings from large groups of women that allowed the committee to feel confident that moderate caffeine intake was safe. - Reuters