Maternal caffeine consumption raises miscarriage risk
Source: American Journal of Obstetrics & Gynecology 2008; Advance online publication

Examining the effect of caffeine intake during pregnancy on the risk for miscarriage.

MedWire News: Expectant mothers who consume intakes of caffeine equivalent to two cups of coffee a day may increase their risk for miscarriage, US researchers suggest.

The Food Standards Agency advises pregnant women to consume no more than 300 mg of caffeine, or four cups of coffee, a day.

But current research, led by De-Kun Li (Kaiser Foundation Research Institute, Oakland, California) found that more than 200 mg of caffeine a day doubled the risk for miscarriage in comparison with no caffeine.

The researchers interviewed 1,063 pregnant women up until 20 weeks' gestation about their daily caffeine intake. Of these women, 264 consumed no caffeine, 635 had a caffeine intake of less than 200 mg/day, and 164 consumed at least 200 mg/day.

Women who consumed less than 200 mg/day had a slightly increased risk for miscarriage, while women who consumed at least 200 mg of caffeine daily had a 2.23-fold increased risk.

Expectant mothers who consumed caffeine were 2.04 times more likely to experience a miscarriage if they were non-smokers, and were 2.33 times more likely to face a miscarriage if they had no prior history of miscarriage.

Nausea or vomiting symptoms during pregnancy and inconsistent caffeine intakes did not affect the association between caffeine intake and miscarriage.

"Therefore, it may be prudent to stop or reduce caffeine intake during pregnancy," conclude De-Kun Li et al.