Against the odds: Endometriosis linked to four times higher pregnancy rates than other causes of infertility, new study reveals
A landmark 30-year study of over four million women in England has revealed that women with endometriosis-associated infertility are significantly more likely to become pregnant compared to those with infertility from other causes.
Presented today at the 41st Annual Meeting of the European Society of Human Reproduction and Embryology (ESHRE), the findings offer renewed optimism for millions of women living with endometriosis who are hoping to conceive.
Endometriosis is a long-term condition in which tissue similar to the lining of the womb grows outside the womb, often causing severe pelvic pain and infertility. Globally, it is estimated to affect 190 million women and is recognised as a leading cause of infertility.
This study was conducted as part of the EU FEMaLe (Finding Endometriosis through Machine Learning) consortium. Led by Dr. Lucky Saraswat from the Aberdeen Centre of Women’s Health Research, University of Aberdeen, together with researchers from the Centre for Reproductive Health at the University of Edinburgh, the research team carried out the largest and longest population-based study of its kind, analysing linked primary care, secondary care and maternity records for more than four million women in England who presented with infertility or symptoms related to endometriosis between 1991 and 2020.
Of the 4,041,770 women aged 13-50 years who attended primary care with infertility (n=245,994) or other symptoms of endometriosis, 111,197 had a surgically confirmed diagnosis of endometriosis via laparoscopy or laparotomy over the 30-year period. The overall population prevalence of female infertility across the population during the study period was 48.9 per 1,000 women, with highest rates observed among women aged 30 to 39.
Among those with infertility, 6.1% (14,904) had surgically confirmed endometriosis. Of these, 57.4% (8,556) experienced infertility before their diagnosis, underlining the ongoing delays in recognition and diagnosis of endometriosis.
The study reaffirmed a strong association between the condition and fertility challenges, showing that women with infertility were more than twice as likely to be diagnosed with endometriosis compared to women without infertility.
However, when examining pregnancy outcomes, women with endometriosis-associated infertility had a four times higher chance of conception compared to women with infertility from other causes, including ovulatory dysfunction, tubal factors, and unexplained infertility. In total, 40.5% of women with an endometriosis diagnosis (regardless of their infertility status) had at least one pregnancy during the study period.
Reflecting on the potential explanations for this result, Dr. Saraswat said, “Endometriosis can vary in how it affects fertility. Women with milder forms may retain good reproductive potential, especially if the condition is diagnosed and managed early. There’s also moderate-quality evidence suggesting that laparoscopic surgery can improve pregnancy rates in some with endometriosis.”
She added that women with the condition may also be more likely to seek help earlier because of heightened awareness about the link between endometriosis and infertility.
“While fertility remains multifactorial, with factors such as age playing a significant role, our findings offer robust, evidence-based data that can significantly enhance fertility counselling for women newly diagnosed with endometriosis – including information on the likelihood of infertility, overall pregnancy rates and outcomes, and how those outcomes compare to other causes of infertility.”
“These insights can empower women to make informed reproductive decisions”, she said. “They also provide a strong foundation for future research into how factors such as disease stage, site, surgical treatment and use of assisted reproduction influence pregnancy outcomes in women with endometriosis.”
Professor Dr. Anis Feki, Chair-Elect of ESHRE, commented, “This study shows that women with endometriosis-related infertility are significantly more likely to conceive than those with other infertility causes. These findings provide valuable reassurance for patients and underscore the importance of early diagnosis and tailored treatment strategies.”
Reference:
Against the odds: Endometriosis linked to four times higher pregnancy rates than other causes of infertility, new study reveals, European Society of Human Reproduction and Embryology, Meeting: ESHRE 41st Annual Meeting.
