{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T03:01:11Z","timestamp":1777863671106,"version":"3.51.4"},"reference-count":10,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T00:00:00Z","timestamp":1777507200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Reprod. Health"],"abstract":"\n Introduction<\/jats:title>\n Assisted reproductive technology (ART) practice varies widely across centers and evolves rapidly, often outpacing the generation of randomized evidence. OPERA (Observational ProjEct for a Research database for ART procedures) was developed to create a harmonized, multinational real-world database derived from routine clinical ART documentation and to provide a structured overview of contemporary clinical practice.<\/jats:p>\n <\/jats:sec>\n \n Materials and methods<\/jats:title>\n OPERA is a retrospective, multicenter database including 18 IVF\/ICSI centers (9 in Italy and 9 in Germany) using a shared electronic platform (Meditex). All second- and third-level ART cycles performed between January 1, 2016 and December 31, 2020 were eligible for inclusion. Data were extracted from Meditex, harmonized into four relational domains (Baseline, Stimulation, Laboratory, and Pregnancy outcomes), and anonymized prior to aggregation. After data cleaning (duplicate removal, exclusion of unlinked frozen embryo transfer cycles, and cycles with incomplete follow-up), 64,081 ovarian stimulation cycles and 31,027 intended frozen embryo transfer cycles were included. Analyses were descriptive, and no imputation was performed.<\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n Median female age was 37 years (IQR 33\u201339), and median BMI was 22.7\u2005kg\/m\u00b2. Antagonist protocols were used in 78.4% of cycles. Clinical pregnancy rates were 33.8% for fresh embryo transfers and 34.2% for frozen embryo transfers, with corresponding live birth rates of 25.8% and 24.3%.<\/jats:p>\n <\/jats:sec>\n \n Discussion<\/jats:title>\n OPERA provides a large, harmonized real-world ART dataset enabling a comprehensive overview of clinical practice across multiple centers. While the descriptive design does not allow causal inference, it supports benchmarking and hypothesis generation for future analytical studies, acknowledging inherent limitations related to variable completeness and privacy-preserving data structure.<\/jats:p>\n <\/jats:sec>","DOI":"10.3389\/frph.2026.1822310","type":"journal-article","created":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T05:29:41Z","timestamp":1777526981000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["The OPERA project: a harmonized multinational real-world ART database across Italy and Germany (2016\u20132020) and a descriptive snapshot of contemporary clinical practice"],"prefix":"10.3389","volume":"8","author":[{"given":"Andrea","family":"Francavilla","sequence":"first","affiliation":[{"name":"FROM - Research Foundation Bergamo Hospital - ETS","place":["Bergamo, Italy"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chiara","family":"Pavoni","sequence":"additional","affiliation":[{"name":"FROM - Research Foundation Bergamo Hospital - ETS","place":["Bergamo, Italy"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mariangela","family":"Fumarola","sequence":"additional","affiliation":[{"name":"FROM - Research Foundation Bergamo Hospital - ETS","place":["Bergamo, Italy"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eleonora","family":"Sfreddo","sequence":"additional","affiliation":[{"name":"FROM - Research Foundation Bergamo Hospital - ETS","place":["Bergamo, Italy"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Francesco Maria","family":"Fusi","sequence":"additional","affiliation":[{"name":"Department of Maternal Fetal and Pediatric Medicine, ASST Papa Giovanni XXIII","place":["Bergamo, Italy"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"name":"OPERA Working Group","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,4,30]]},"reference":[{"key":"B1","year":"2023"},{"key":"B2","doi-asserted-by":"publisher","first-page":"2293","DOI":"10.1056\/NEJMsb1609216","article-title":"Real-world evidence\u2014what is it and what can it tell US?","volume":"375","author":"Sherman","year":"2016","journal-title":"N Engl J Med"},{"key":"B3","doi-asserted-by":"publisher","first-page":"hoaa032","DOI":"10.1093\/hropen\/hoaa032","article-title":"ART In Europe, 2016: results generated from European registries by ESHRE","volume":"2020","author":"Wyns","year":"2020","journal-title":"Hum Reprod Open"},{"key":"B4","doi-asserted-by":"publisher","first-page":"102915","DOI":"10.1016\/j.eclinm.2024.102915","article-title":"Real-world data: bridging the gap between clinical trials and practice","volume":"78","author":"Wilson","year":"2024","journal-title":"EClinicalMedicine"},{"key":"B5","doi-asserted-by":"publisher","first-page":"1453","DOI":"10.1016\/S0140-6736(07)61602-X","article-title":"The strengthening the reporting of observational studies in epidemiology (STROBE) statement: guidelines for reporting observational studies","volume":"370","author":"von Elm","year":"2007","journal-title":"Lancet"},{"key":"B6","doi-asserted-by":"publisher","first-page":"e1001885","DOI":"10.1371\/journal.pmed.1001885","article-title":"The REporting of studies conducted using observational routinely-collected health data (RECORD) statement","volume":"12","author":"Benchimol","year":"2015","journal-title":"PLoS Med"},{"key":"B7","doi-asserted-by":"publisher","first-page":"393","DOI":"10.1016\/j.fertnstert.2017.06.005","article-title":"The international glossary on infertility and fertility care, 2017","volume":"108","author":"Zegers-Hochschild","year":"2017","journal-title":"Fertil Steril"},{"key":"B8","first-page":"1","article-title":"European Parliament and Council of the European Union. Regulation (EU) 2016\/679 of the European parliament and of the council of 27 April 2016 on the protection of natural persons with regard to the processing of personal data and on the free movement of such data (general data protection regulation)","year":"2016","journal-title":"Offic J Eur Union"},{"key":"B9","doi-asserted-by":"publisher","first-page":"144","DOI":"10.1136\/amiajnl-2011-000681","article-title":"Methods and dimensions of electronic health record data quality assessment: enabling reuse for clinical research","volume":"20","author":"Weiskopf","year":"2013","journal-title":"J Am Med Inform Assoc"},{"key":"B10","doi-asserted-by":"publisher","first-page":"hoaa009","DOI":"10.1093\/hropen\/hoaa009","article-title":"ESHRE Guideline: ovarian stimulation for IVF\/ICSI","volume":"2020","author":"Bosch","year":"2020","journal-title":"Hum Reprod Open"}],"container-title":["Frontiers in Reproductive Health"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/frph.2026.1822310\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T05:29:42Z","timestamp":1777526982000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/frph.2026.1822310\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,30]]},"references-count":10,"alternative-id":["10.3389\/frph.2026.1822310"],"URL":"https:\/\/doi.org\/10.3389\/frph.2026.1822310","relation":{},"ISSN":["2673-3153"],"issn-type":[{"value":"2673-3153","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,30]]},"article-number":"1822310"}}