Researchers found that the risk of stillbirth was three times greater among pregnant women who said they drank five or more times per week, compared with those who reported having less than one drink a week. But there was "little if any association" between alcohol intake and the risk of infant death, they report in the February 15th issue of the American Journal of Epidemiology.

Alcohol use during pregnancy is known to raise the risk of physical, mental and behavioral problems in infants and children. Because there is no known "safe" level of alcohol exposure for the fetus, women are advised to completely abstain from drinking while pregnant.

The specific impact drinking has on the odds of stillbirth and newborn and infant death has been unclear, however, according to Dr. Ulrik Kesmodel, of Aarhus University Hospital in Denmark, and colleagues.

So the investigators looked at alcohol use, as well as smoking, caffeine intake, age and other factors, among 24,768 women with singleton pregnancies between 1989 and 1996.

Overall, there were 116 stillbirths and 119 infant deaths by age 1, Kesmodel's team found. The risk of stillbirth rose in tandem with alcohol use, but showed the steepest increase among the relatively few women who had five or more drinks each week. There was a trend toward higher infant mortality risk among these women as well, but the link was not significant, the report indicates.

The researchers note that the higher risk of stillbirth in this study appeared to be largely due to "fetoplacental dysfunction," which includes problems such as intrauterine growth retardation, complications related to the umbilical cord, and a cut-off of oxygen to the fetus.

The rate of stillbirth due to such problems was nearly 9 per 1,000 births among women who had five or more drinks a week, compared with just over 1 stillbirth per 1,000 among women who reported less than one drink per week.

SOURCE: American Journal of Epidemiology 2002;155:305-312.