Multivitamins Reduce Risk of Miscarriage

Bad News first: A woman is more likely to miscarry if she and her partner drink more than two caffeinated beverages a day during the weeks leading up to conception, according to a new study from researchers at the National Institute of Health and Ohio State University, Columbus. Similarly, women who drank more than two daily caffeinated beverages during the first seven weeks of pregnancy were also more likely to miscarry.

The Good News? Women who took a daily multivitamin before conception and through early pregnancy were less likely to miscarry than women who did not.

"Our findings provide 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 first author, Germaine Buck Louis, Ph.D., director of the Division of Intramural Population Health Research at NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development.

Researchers compared such lifestyle factors as cigarette use, caffeinated beverage consumption and multivitamin use among 344 couples with a singleton pregnancy from the weeks before they conceived through the seventh week of pregnancy.

The researchers reported their results using a statistical concept known as a hazard ratio, which estimates the chances of a particular health outcome occurring during the study time frame. For example, the researchers evaluated caffeinated beverage consumption in terms of the daily likelihood of pregnancy loss over a given time period. A score greater than 1 indicates an increased risk for pregnancy loss each day following conception, and a score less than 1 indicates a reduced daily risk.

Of the 344 pregnancies, 98 ended in miscarriage, or 28 percent. For the preconception period, miscarriage was associated with female age of 35 or above, for a hazard ratio of 1.96 (nearly twice the miscarriage risk of younger women). The study was not designed to conclusively prove cause and effect. The study authors cited possible explanations for the higher risk, including advanced age of sperm and egg in older couples or cumulative exposure to substances in the environment, which could be expected to increase as people age.

Because their study found caffeine consumption before pregnancy was associated with a higher risk of miscarriage, it's more likely that caffeinated beverage consumption during this time directly contributes to pregnancy loss.

"Our findings also indicate that the male partner matters, too," Dr. Buck Louis said. "Male preconception consumption of caffeinated beverages was just as strongly associated with pregnancy loss as females.'"

Finally, the researchers saw a reduction in miscarriage risk for women who took a daily multivitamin. During the preconception period, researchers found a hazard ratio of .45-55 percent reduction in risk for pregnancy loss. Women who continued to take the vitamins through early pregnancy had a hazard ratio of 0.21, or a risk reduction of 79 percent. The authors cited other studies that found that vitamin B6 and folic acid - included in preconception and pregnancy vitamin formulations - can reduce miscarriage risk. Folic acid supplements are recommended for women of childbearing age, as their use in the weeks leading up to and following conception reduces the risk for having a child with a neural tube defect.