Evaluating the landscape and characteristics of endometriosis research published between 1990 and 2024

Purpose We aimed to assess the landscape of endometriosis randomised-controlled trials (RCTs) between 1990 and 2024 by characterising RCTs by management type, primary outcome, country of origin, trial registration, sample size and minimum detectable difference based upon standard RCT power targets of 80% and 90%.

We identified all endometriosis RCTs from Dimensions.AI with an English abstract. Articles were examined for sample size, theme and primary outcome. Sample sizes were used to calculate minimum detectable effect size (MDES) of studies at 80% and 90% power.

We analysed 536 RCTs using ‘R’. 55.6% (N = 298) of studies investigated medical management of endometriosis, of which 177 investigated Gonadotrophin Releasing Hormone (GnRH) analogues. RCTs investigating complementary therapies rose from 0.847% (N = 1) in 1990–1999 to 28.7% (N = 31) of medical management RCTs in 2020–2024. The US and China led publishing with 70 and 65 RCTs total, respectively. Importantly, of 445 RCTs with at least one continuous outcome, we found that at 90% power, 55.7% (N = 248) of RCTs would only detect a standardised mean difference which was ‘large’ or greater.

We noted several trends within endometriosis RCTs. In line with wider literature, China accounts for a growing proportion of RCTs. Although complementary therapy is increasingly recognised as a management option requiring further research, most medical management RCTs focussed on GnRH analogues as part of their treatment regime despite these being considered second-line management options. A high proportion of RCTs was underpowered to detect potentially clinically significant effects of intervention—potentially indicating significant resource wastage. Similar content being viewed by others Funding Open Access funding enabled and organized by CAUL and its Member Institutions. The authors declare that no funds, grants, or other supports were received during the preparation of this manuscript. Author information Authors and Affiliations Corresponding author Ethics declarations Conflict of interest QF reports scholarships from Merck, Monash University, and China Scholarship Council. BWM reports consultancy, travel support, and research funding from Merck and consultancy for Ferring, Organon, and Norgine. Additional information Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Supplementary Information Below is the link to the electronic supplementary material. Rights and permissions Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. About this article Cite this article Mago, S., Grimes, D.R., Feng, Q. et al. Evaluating the landscape and characteristics of endometriosis research published between 1990 and 2024. Arch Gynecol Obstet (2026). https://doi.org/10.1007/s00404-026-08516-x Received: Accepted: Published: DOI: https://doi.org/10.1007/s00404-026-08516-x