Caffeine consumption linked to risk of miscarriage

Parents-to-be who consume too much caffeine during sensitive times of fetal development are at greater risk of a miscarriage, researchers from the National Institutes of Health and Ohio State University, Columbus, have found.

Using data from the Longitudinal Investigation of Fertility and the Environment Study, NIH researchers compared lifestyle factors as cigarette use, caffeinated beverage consumption, and multivitamin use among 344 couples with a single pregnancy, from weeks before conception through the seventh week of pregnancy.

They found that a woman is more likely to miscarry if she and her partner drank more than two caffeinated beverages a day during the weeks leading up to conception. If a woman drank more than two daily caffeinated beverages during the first seven weeks of pregnancy, she was also more likely to miscarry.

Of the 344 pregnancies, 98 ended in miscarriage, or about 28 percent.

“Our findings prove useful information for couples who are planning a pregnancy and who would like to minimize their risk for early pregnancy loss,” said the study’s lead author, Germaine Buck Louis, director of the Division of Intramural Population Health Research at NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development, in a statement. "Our findings also indicate that the male partner matters, too. Male preconception consumption of caffeinated beverages was just as strongly associated with pregnancy loss as females.”

Miscarriage was also linked to older mothers, over age 35, who experienced nearly twice the miscarriage risk of younger women.

Researchers also found, however, a reduction in miscarriage risk for women who took a daily multivitamin. If the mother took a multivitamin during the preconception period, there was a 55 percent reduction in risk of pregnancy loss. If they continued to take it during early pregnancy, there was an even greater reduction.

"For women, there was almost an 80 percent reduction in risk of miscarriage just by taking a multivitamin, if she took it daily while she was trying to become pregnant and in the first seven weeks of pregnancy," Louis, the lead author, said, adding there was no association in men taking a multivitamin.

The study authors said other research has shown that vitamin B6 and folic acid can reduce miscarriage risk as well as the chances of having a baby with a neural tube defect, a serious health complication.

The study was published online in Fertility and Sterility.