Women who are thinking about becoming pregnant are usually advised to stay away from alcoholic beverages. Now, new research suggests that their partners should do the same.

In a Danish study, alcohol drinking by men or women during the conception period increased the likelihood of a miscarriage.

Studies in animals have suggested that high doses of alcohol given to males and females around the time of conception or early in the pregnancy increase fetal death, but the association has been less clear in humans.

Dr. Tine Brink Henriksen, of Aarhus University Hospital in Denmark and colleagues followed 430 couples who were attempting a first-time pregnancy. The study participants were all 20 to 35 years old.

A total of 186 pregnancies occurred during the study period, of which 55 ended in spontaneous abortion and 131 resulted in childbirth, the investigators report in the American Journal of Epidemiology.

Women who reported consuming 10 or more drinks per week at the time of conception were nearly three times more likely to experience a miscarriage than those who had not consumed any wine, spirits, or beer at the time of conception.

When men consumed 10 or more weekly drinks at the time of conception, their partners’ risk of spontaneous abortion was up to five times greater than it was for women whose male partners did not drink, the report indicates.

“It was quite surprising that we found such a strong association, no study has ever been able to show this previously,” Henriksen commented to Reuters Health.

The reason for the association between men’s drinking and spontaneous abortion is not fully understood. However, studies have shown that alcohol consumption is associated with chromosomal abnormalities in sperm cells, and many aborted fetuses are known to have chromosomal abnormalities.

What’s more, the concentration of alcohol in semen - where its presence can be detected relatively quickly after it is ingested - is similar to its concentration in the blood, the researchers note.

“In conclusion, we found that both male and female alcohol intakes during the week of conception increased the risk of spontaneous abortion,” Henriksen and colleagues write.

“The primary implication,” Henriksen said, “is that we should perhaps in future research look much more into the impact of male exposures on early pregnancy outcome or infertility problems.”

Asked about specific recommendations, the researcher said: “Prior to giving advise I would very much like to see and encourage more research to replicate our findings - we do have the largest study ever on this particular matter, but still - the findings were a bit surprising and it is an observational study.”

Although the study found that having 10 or more drinks was associated with spontaneous abortions, Dr. George Benjamin, executive director of the American Public Health Association says he does not want women thinking they can safely consume up to nine drinks per week.

On the other hand, Benjamin, who was not involved with the study, said the findings can be used to reassure women who, for example, consumed alcohol at a dinner party two weeks before finding out they were pregnant.

“If I was their doctor,” he told Reuters Health, “I could comfort them more and advise them more about the outcome of their pregnancy.”

Still, “I did not say it (alcohol drinking) was safe,” Benjamin said. He added that since it is known that alcohol consumption can contribute to birth defects, prematurity, low birthweight, and fetal alcohol syndrome, prevention of these conditions is very important.

“If we can get people to stop drinking during pregnancy,” he said, it would “impact on those birth defects.”

SOURCE: American Journal of Epidemiology, October 1, 2004.