7 Healthcast: Caffeine and miscarriage

Cold or hot, we love our coffee, and pregnant women are no different.

But a new Kaiser Permanente study may make moms-to-be think twice about grabbing a cup of joe.

Researchers found pregnant women who consumed 200 milligrams of caffeine -about two cups of coffee- or more a day had more than double the risk of miscarriage compared with pregnant women who had no caffeine.

And the risk is the same whether you get your caffeine from coffee, tea or in sodas.

"Regardless of where the caffeine came from, as long as you're intake went above 200 milligrams the risk of miscarriage is increased," said lead investigator Dr. De-kun Li.

Dr. Li studied more than a thousand bay area Kaiser patients from early pregnancy until birth.

So why does caffeine pose a risk to baby? A high does of caffeine may constrict a mother's blood vessels.

"If mother's blood vessel contracts too severely, the theory is that it can reduce blood flow to placenta," Dr. Li said.

"The kind of advice I might give my patient is to limit to one cup a day and take out all caffeine beverages particularly during the first three months," said Dr. Tracy Flanagan of Kaiser Permanente.

The study also showed even women who drank less than two cups of coffee a day still had a miscarriage rate that was higher than women who didn't have any caffeine during pregnancy.

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