A key cause of multiple miscarriages has been identified by British researchers, who said that a simple surgical procedure could help women carry their pregnancies to full term.

Scientists from the University of Sheffield in northern England said Wednesday that they have "firm evidence" that removing fibroids -- benign tumors -- from the womb could help dramatically reduce the risk of miscarriage.

Fibroids affect one in four women in their lifetime and some kinds can distort the inside of the womb, the researchers said.

The 20-year study, published in the journal Human Reproduction, followed 966 women who had suffered three or more miscarriages in a row.

Cavity-distorting submucosal fibroids were surgically removed from 25 of the women and miscarriage rates in their subsequent pregnancies during the second trimester fell from 21.7 percent to 0 percent.

This translated to an increase in the live birth rate from 23.3 percent to 52 percent.

Dr. Sotirios Saravelos, clinical research fellow at the university, said, "This is the first time that it has been shown that removing fibroids that distort the uterine cavity may increase the chances of a subsequent live birth in women with recurrent miscarriages."

The team hopes to continue their research in larger studies.