A new blood test for the painful uterine disorder endometriosis detected cases missed by ultrasound and MRI, according to results of a study to be presented at a medical meeting this week.

Endometriosis, in which cells similar to the lining of the uterus grow outside the uterus, affects about 1 in 10 women of reproductive age, causing pelvic pain, menstrual irregularities, dyspareunia, or pain associated with sexual intercourse, and gastrointestinal discomfort.

Diagnosis can take years, largely because imaging tests don't detect it accurately, and the current gold standard diagnostic method involves laparoscopic surgery.

Studying 298 reproductive-age women who had surgery to look for endometriosis, including 177 with confirmed cases, researchers found the blood test accurately identified 80% of those cases and accurately ruled out the disease in 97.5% of individuals who did not have it.

The test developed by HerAnova Lifesciences also correctly identified 61.5% of cases that had been missed on imaging studies, according to a report of the study published in the Journal of Minimally Invasive Gynecology.

“Endometriosis remains profoundly underdiagnosed, and patients deserve better tools,” HerAnova Chief Medical Officer Farideh Bischoff said in a statement.

The researchers are scheduled to report on the study at the American & Global College of Endometriosis Specialists Annual Meeting in Las Vegas.

“We look forward to presenting our findings to the clinical and scientific community and advancing the conversation around non-invasive approaches for evaluating this disease,” Bischoff said.