A relatively common condition associated with abdominal pain, heavy periods, and infertility may increase risk of miscarriage by over 75 percent, a new research has found.

The study involving over 14,000 women in Britain looked at the risk posed by endometriosis – a condition in which cells from the lining of the uterus (endometrium) are found elsewhere in the pelvic area.

“These results indicate that endometriosis pre-disposes women to an increased risk of early pregnancy loss and later pregnancy complications,” said the study’s first author Lucky Saraswat, consultant gynaecologist from the Aberdeen Royal Infirmary, Britain.

The study was a nationwide cohort study using discharge data from all state hospitals in Scotland. Records of women with and without a confirmed diagnosis of endometriosis were cross-linked to their maternity records to evaluate pregnancy outcomes.

A total of 14,655 women were included in the analysis, with their medical records followed-up for a maximum of 30 years between 1981 and 2010.

After adjustments for age and previous pregnancy, results showed that women with endometriosis had a significantly higher risk of early pregnancy complications than the controls.

This risk was 76 percent higher for miscarriage and nearly three-times higher for ectopic pregnancy.

The findings should now be taken into account when counselling women with endometriosis about their family plans and care during pregnancy, the researchers noted.

Suggesting a possible explanation for the risk, Saraswat said that endometriosis is associated with increased inflammation in the pelvis, and structural and functional changes in the lining of the uterus.

“We believe such changes in the pelvic and uterine environment could influence implantation and development of placenta, pre-disposing them to adverse pregnancy outcomes,” she said.

Details of the study are scheduled to be reported this week at ESHRE 205, held in Lisbon, Portugal from June 14-17.