Science News Archive

Pregnancy-Caffeine Combo Bad Idea

Researchers have shown that caffeine exposure is linked to an increase risk of miscarriage.

De-Kun Li, from Californian health insurer Kaiser-Permanente, followed 1063 women during the first twenty weeks of their pregnancies or until they had a miscarriage. Amongst the details collected, the participants were asked about their caffeine consumption.  The data is published in the American Journal of Obstetrics and Gynecology and shows that women drinking more than 200 milligrams of caffeine per day - the equivalent to just over one cup of coffee - had a two-fold rise in their miscarriage risk.

But it wasn't just coffee that was to blame - all caffeinated beverages including fizzy drinks, tea and even hot chocolate had the same effect.  According to Li, caffeine might be triggering vaso-constriction - blood vessel narrowing - in the placenta, cutting blood flow and the delivery of oxygen and collection of waste products from the developing foetus.  Alternatively, he says, caffeine may be directly toxic to a foetus.  Either way he suggests that women avoid caffeine altogether during pregnancy. "It's not a big sacrifice," he says.

27th Jan 2008