Cumulative live birth rates in women with endometriosis undergoing ART treatment.

STUDY QUESTION How do cumulative live birth rates (CLBRs) in women with endometriosis compare to those with other infertility diagnoses undergoing ART? SUMMARY ANSWER Women with endometriosis as the sole cause of infertility achieved higher CLBRs compared to those with additional infertility diagnoses (endometriosis-plus) or other non-endometriosis causes of infertility. WHAT IS KNOWN ALREADY Endometriosis affects approximately 10% of women of reproductive age and is a major cause of infertility, with many women resorting to ART treatments in the hope of achieving a pregnancy. However, the comparative success rates of ART for these women, compared to those with other causes of infertility is not well understood. STUDY DESIGN, SIZE, DURATION This retrospective cohort study included 79 318 women who initiated autologous ART between 2014 and 2019 in Australia and New Zealand, with follow-up through 2021 or the first live birth. PARTICIPANTS/MATERIALS, SETTING, METHODS Participants were categorized into three groups based on infertility diagnosis: endometriosis-only (n = 4311), endometriosis-plus (n = 6312; endometriosis with other infertility factors) and other-infertility (n = 68 695; no endometriosis). Conservative and optimal CLBRs were calculated based on assumptions made about the chance of live birth for women who discontinued treatment. MAIN RESULTS AND THE ROLE OF CHANCE Endometriosis was reported as the sole cause of infertility in 5% of women (endometriosis-only), while 8% had endometriosis with other diagnoses (endometriosis-plus). The remaining women had either other causes of infertility (63%) or unexplained infertility (24%). Depending on assumptions made regarding patients who discontinued treatment, the CLBR by the sixth complete cycle for women diagnosed with endometriosis-only ranged from 64% to 83%; for women with an endometriosis-plus diagnoses, the CLBR ranged from 54.3% to 68.7%; and for women without endometriosis, the CLBR ranged from 57.3% to 76.5%. Compared to women without endometriosis, the live birth rate was 6% higher in endometriosis-only group (RR: 1.06; 95% CI: 1.04-1.08) and 5% lower in endometriosis-plus group (RR: 0.95; 95% CI: 0.93-0.97). Compared to the endometriosis-only group, pregnancy loss was 46% higher (RR: 1.46; 95% CI: 1.35-1.59) in endometriosis-plus group. LIMITATIONS, REASONS FOR CAUTION The study did not assess endometriosis severity or phenotype, which may influence ART outcomes. WIDER IMPLICATIONS OF THE FINDINGS These findings provide critical data for counselling women with endometriosis regarding ART success. The higher CLBR in the endometriosis-only group suggests that isolated endometriosis does not negatively impact ART outcomes and highlights the need for tailored management in women with additional infertility factors. STUDY FUNDING/COMPETING INTEREST(S) This study is funded through the Medical Research Future Fund (MRFF) Research Data Infrastructure grant (MRFRFD000065). The sponsors had no role in the design and conduct of the study; data collection, management, analysis and interpretation; manuscript preparation, review, or approval; or the decision to submit for publication. FSANZ contracts National Perinatal Epidemiology and Statistics Unit (NPESU) of the University of New South Wales (UNSW) to prepare annual reports and benchmarking reports from the Australian and New Zealand Assisted Reproductive Technology Database (ANZARD): one of those datasets is used in this study. R.C.P. is a Research Fellow of the NPESU, UNSW. G.M.C. is the Director of the NPESU, UNSW. J.A. reports support from the Medical Research Future Fund and the Australian Government Department of Health and Aged Care, consulting fees from Hologic and Gedeon Richter, honoraria from Hologic, and advisory board participation with Gedeon Richter. G.D.M. reports funding from the NHMRC and the Australian Government Department of Health and Aged Care and is lead editor of a book published by Oxford University Press. C.N. reports institutional funding, an unpaid leadership role with ACTA and is a former employee of CSL Vifor. R.D., A.H., and I.R. declare no conflicts of interest. TRIAL REGISTRATION NUMBER N/A.