London ? Pregnant women who drink eight or more cups of coffee a day could double their risk of stillbirth compared with pregnant women who do not drink coffee, new research suggests.

However, experts cautioned that the findings, published this week in the British Medical Journal, were tenuous and several factors other than coffee could explain the results.

Previous studies have linked the consumption of more than three or four cups of coffee a day with miscarriage and low birth weight.

“Women should not be worried because this study has serious limitations,” said Lisa Signorello, an epidemiologist at the International Epidemiology Institute in Rockville, Md., and an assistant professor of medicine at Vanderbilt University in Nashville, Tenn.

Stillbirths are rare, occurring in less than 1 percent of pregnancies. The findings in this Danish study are based on 11 stillbirths among 950 women drinking eight or more cups of coffee a day, and scientists do not like to draw firm conclusions from numbers that low.

The study, conducted by scientists at Aarhus University, involved 18,478 pregnant women attending the obstetrics department at the university hospital between 1989 and 1996.

One in 250 pregnancies ended in stillbirth among women who drank no coffee during their pregnancy.

But three in 250 pregnancies ended in stillbirth among the 950 women who drank more than eight cups daily.