{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,1]],"date-time":"2026-11-01T11:38:56Z","timestamp":1793533136381,"version":"4.5.0"},"reference-count":15,"publisher":"Elsevier BV","license":[{"start":{"date-parts":[[2025,8,1]],"date-time":"2025-08-01T00:00:00Z","timestamp":1754006400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.elsevier.com\/tdm\/userlicense\/1.0\/"},{"start":{"date-parts":[[2025,8,1]],"date-time":"2025-08-01T00:00:00Z","timestamp":1754006400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.elsevier.com\/legal\/tdmrep-license"},{"start":{"date-parts":[[2025,6,13]],"date-time":"2025-06-13T00:00:00Z","timestamp":1749772800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"name":"Research Unit, Holbaek Hospital, Denmark"}],"content-domain":{"domain":["clinicalkey.com","clinicalkey.com.au","clinicalkey.es","clinicalkey.fr","clinicalkey.jp","ejog.org","elsevier.com","sciencedirect.com"],"crossmark-restriction":true},"short-container-title":["European Journal of Obstetrics &amp; Gynecology and Reproductive Biology"],"published-print":{"date-parts":[[2025,8]]},"DOI":"10.1016\/j.ejogrb.2025.114526","type":"journal-article","created":{"date-parts":[[2025,6,10]],"date-time":"2025-06-10T19:18:56Z","timestamp":1749583136000},"page":"114526","update-policy":"https:\/\/doi.org\/10.1016\/elsevier_cm_policy","source":"Crossref","is-referenced-by-count":2,"special_numbering":"C","title":["Evaluating the performance of the M6 model without initial serum progesterone (M6NP) and the NICE guidelines in a Danish pregnancy of unknown location (PUL) population"],"prefix":"10.1016","volume":"312","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0754-855X","authenticated-orcid":false,"given":"Carni","family":"Reza","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mette Schou","family":"Hammerum","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Solveig Johanna","family":"Michaud","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Niels","family":"Klarskov","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ilda","family":"Amirian","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"78","reference":[{"key":"10.1016\/j.ejogrb.2025.114526_b0005","unstructured":"Kirk E, Bottomley C, Bourne T. Diagnosing ectopic pregnancy and current concepts in the management of pregnancy of unknown location."},{"issue":"3","key":"10.1016\/j.ejogrb.2025.114526_b0010","doi-asserted-by":"crossref","first-page":"857","DOI":"10.1016\/j.fertnstert.2010.09.006","article-title":"Pregnancy of unknown location: a consensus statement of nomenclature, definitions, and outcome","volume":"95","author":"Barnhart","year":"2011","journal-title":"Fertil Steril"},{"key":"10.1016\/j.ejogrb.2025.114526_b0015","doi-asserted-by":"crossref","unstructured":"Kirk E, Condous G, Bourne T. Pregnancies of unknown location. Best Pract Res Clin Obstet Gynaecol [Internet]. 2009 Aug [cited 2024 Sep 26];23(4):493\u20139. Available from: https:\/\/pubmed.ncbi.nlm.nih.gov\/19345646\/.","DOI":"10.1016\/j.bpobgyn.2009.01.008"},{"key":"10.1016\/j.ejogrb.2025.114526_b0020","unstructured":"IOTA \u2013 PUL model [Internet]. [cited 2024 Sep 26]. Available from: https:\/\/homes.esat.kuleuven.be\/\u223csistawww\/biomed\/earlypregnancycare\/m6\/index.html."},{"key":"10.1016\/j.ejogrb.2025.114526_b0025","doi-asserted-by":"crossref","unstructured":"Van Calster B, Bobdiwala S, Guha S, Van Hoorde K, Al-Memar M, Harvey R, et al. Managing pregnancy of unknown location based on initial serum progesterone and serial serum hCG levels: development and validation of a two-step triage protocol. Ultrasound Obstet Gynecol [Internet]. 2016 Nov 1 [cited 2024 Sep 26];48(5):642\u20139. Available from: https:\/\/pubmed.ncbi.nlm.nih.gov\/26776599\/.","DOI":"10.1002\/uog.15864"},{"key":"10.1016\/j.ejogrb.2025.114526_b0030","doi-asserted-by":"crossref","unstructured":"Hahlin M, Sjoblom P, Lindblom B. Combined use of progesterone and human chorionic gonadotropin determinations for differential diagnosis of very early pregnancy. Fertil Steril [Internet]. 1991 [cited 2024 Oct 4];55(3):492\u2013Available from: https:\/\/pubmed.ncbi.nlm.nih.gov\/2001750\/.","DOI":"10.1016\/S0015-0282(16)54173-9"},{"issue":"11","key":"10.1016\/j.ejogrb.2025.114526_b0035","doi-asserted-by":"crossref","first-page":"3220","DOI":"10.1093\/humrep\/13.11.3220","article-title":"The accuracy of single serum progesterone measurement in the diagnosis of ectopic pregnancy: a meta-analysis","volume":"13","author":"Mol","year":"1998","journal-title":"Hum Reprod"},{"key":"10.1016\/j.ejogrb.2025.114526_b0040","unstructured":"Ectopic pregnancy and miscarriage: diagnosis and initial management NICE guideline. 2019 [cited 2024 Sep 26]; Available from: www.nice.org.uk\/guidance\/ng126."},{"key":"10.1016\/j.ejogrb.2025.114526_b0045","doi-asserted-by":"crossref","unstructured":"Bobdiwala S, Christodoulou E, Farren J, Mitchell-Jones N, Kyriacou C, Al-Memar M, et al. Triaging women with pregnancy of unknown location using two-step protocol including M6 model: clinical implementation study. Ultrasound Obstet Gynecol [Internet]. 2020 Jan 1 [cited 2024 Sep 26];55(1):105\u201314. Available from: https:\/\/pubmed.ncbi.nlm.nih.gov\/31385381\/.","DOI":"10.1002\/uog.20420"},{"key":"10.1016\/j.ejogrb.2025.114526_b0050","doi-asserted-by":"crossref","unstructured":"Maheut C, Panjo H, Capmas P. Diagnostic accuracy validation study of the M6 model without initial serum progesterone (M6NP) in triage of pregnancy of unknown location. Eur J Obstet Gynecol Reprod Biol [Internet]. 2024 May 1 [cited 2024 Sep 26];296:360\u20135. Available from: https:\/\/pubmed.ncbi.nlm.nih.gov\/38552504\/.","DOI":"10.1016\/j.ejogrb.2024.03.010"},{"key":"10.1016\/j.ejogrb.2025.114526_b0055","doi-asserted-by":"crossref","unstructured":"Fistouris J, Bergh C, Strandell A. Classification of pregnancies of unknown location according to four different hCG-based protocols. Hum Reprod [Internet]. 2016 Oct 1 [cited 2024 Oct 4];31(10):2203\u2013Available from: https:\/\/pubmed.ncbi.nlm.nih.gov\/27580995\/.","DOI":"10.1093\/humrep\/dew202"},{"key":"10.1016\/j.ejogrb.2025.114526_b0060","doi-asserted-by":"crossref","unstructured":"Kirk E, Papageorghiou AT, Condous G, Tan L, Bora S, Bourne T. The diagnostic effectiveness of an initial transvaginal scan in detecting ectopic pregnancy. Hum Reprod [Internet]. 2007 [cited 2024 Oct 28];22(11):2824\u20138. Available from: https:\/\/pubmed.ncbi.nlm.nih.gov\/17855406\/.","DOI":"10.1093\/humrep\/dem283"},{"key":"10.1016\/j.ejogrb.2025.114526_b0065","doi-asserted-by":"crossref","unstructured":"Kirk E, Daemen A, Papageorghiou AT, Bottomley C, Condous G, De Moor B, et al. Why are some ectopic pregnancies characterized as pregnancies of unknown location at the initial transvaginal ultrasound examination? Acta Obstet Gynecol Scand [Internet]. 2008 [cited 2024 Oct 28];87(11):1150\u20134. Available from: https:\/\/pubmed.ncbi.nlm.nih.gov\/18846452\/.","DOI":"10.1080\/00016340802443822"},{"key":"10.1016\/j.ejogrb.2025.114526_b0070","doi-asserted-by":"crossref","unstructured":"Bottomley C, Van Belle V, Mukri F, Kirk E, Van Huffel S, Timmerman D, et al. The optimal timing of an ultrasound scan to assess the location and viability of an early pregnancy. Human Reproduction [Internet]. 2009 Aug 1 [cited 2024 Oct 28];24(8):1811\u20137. Available from: https:\/\/dx.doi.org\/10.1093\/humrep\/dep084.","DOI":"10.1093\/humrep\/dep084"},{"issue":"2","key":"10.1016\/j.ejogrb.2025.114526_b0075","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1002\/uog.2838","article-title":"Pregnancies of unknown location: consensus statement","volume":"28","author":"Condous","year":"2006","journal-title":"Ultrasound Obstet Gynecol"}],"container-title":["European Journal of Obstetrics &amp; Gynecology and Reproductive Biology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.elsevier.com\/content\/article\/PII:S0301211525008024?httpAccept=text\/xml","content-type":"text\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/api.elsevier.com\/content\/article\/PII:S0301211525008024?httpAccept=text\/plain","content-type":"text\/plain","content-version":"vor","intended-application":"text-mining"}],"deposited":{"date-parts":[[2025,11,4]],"date-time":"2025-11-04T19:43:26Z","timestamp":1762285406000},"score":1,"resource":{"primary":{"URL":"https:\/\/linkinghub.elsevier.com\/retrieve\/pii\/S0301211525008024"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,8]]},"references-count":15,"alternative-id":["S0301211525008024"],"URL":"https:\/\/doi.org\/10.1016\/j.ejogrb.2025.114526","relation":{},"ISSN":["0301-2115"],"issn-type":[{"value":"0301-2115","type":"print"}],"subject":[],"published":{"date-parts":[[2025,8]]},"assertion":[{"value":"Elsevier","name":"publisher","label":"This article is maintained by"},{"value":"Evaluating the performance of the M6 model without initial serum progesterone (M6NP) and the NICE guidelines in a Danish pregnancy of unknown location (PUL) population","name":"articletitle","label":"Article Title"},{"value":"European Journal of Obstetrics & Gynecology and Reproductive Biology","name":"journaltitle","label":"Journal Title"},{"value":"https:\/\/doi.org\/10.1016\/j.ejogrb.2025.114526","name":"articlelink","label":"CrossRef DOI link to publisher maintained version"},{"value":"article","name":"content_type","label":"Content Type"},{"value":"\u00a9 2025 The Authors. Published by Elsevier B.V.","name":"copyright","label":"Copyright"}],"article-number":"114526"}}