{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T13:35:57Z","timestamp":1790948157154,"version":"4.1.0"},"reference-count":26,"publisher":"Wiley","issue":"6","license":[{"start":{"date-parts":[[2022,6,1]],"date-time":"2022-06-01T00:00:00Z","timestamp":1654041600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["obgyn.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Ultrasound in Obstet &amp; Gyne"],"published-print":{"date-parts":[[2022,6]]},"abstract":"<jats:title>ABSTRACT<\/jats:title><jats:sec><jats:title>Objectives<\/jats:title><jats:p>Cervical length (CL) measurement \u2264\u200925\u2009mm on mid\u2010trimester ultrasound scan is a known risk factor for preterm birth, for which vaginal progesterone is recommended. The aims of this study were to evaluate whether CL measurement is affected by observer bias and to assess the impact  on short cervix prevalence of masking CL measurement during routine mid\u2010trimester ultrasound scan.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>This was a flash study designed for a 2\u2010month period (October and November 2018) at Cruces University Hospital (Bizkaia, Spain), in which all CL measurements from routine mid\u2010trimester scans were masked. During the study period, there was no modification of the routine screening method, and women with a short cervix were prescribed 200\u2009mg vaginal progesterone daily as per usual. The control group included women examined in a 2\u2010month period  (April and May 2018) prior to the study, in which CL measurements were taken as usual by a non\u2010blinded operator. The primary outcome was the prevalence of short cervix in each group.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>A total of 983 CL measurements were analyzed, including 457 in the blinded group and 526 in the control group. The prevalence of short cervix was 2.7% in the non\u2010blinded group and 5.5% in the blinded group (<jats:italic>P<\/jats:italic>\u2009=\u20090.024). We identified a statistically significant difference in the incidence of CL of 24\u201325\u2009mm between the two groups, with a lower prevalence in the non\u2010blinded <jats:italic>vs<\/jats:italic> blinded group (0.6% <jats:italic>vs<\/jats:italic> 2.4%; <jats:italic>P<\/jats:italic>\u2009&lt;\u20090.005). Moreover, the distribution of CL values was normal in the blinded group, in contrast to the non\u2010blinded group, which was characterized by skewed distribution of CL values.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>Expected\u2010value bias exists and should be taken into account when measuring CL in mid\u2010trimester preterm birth screening. Blinding has demonstrated to be an effective strategy to improve the performance of CL screening in clinical practice. \u00a9 2021 International Society of Ultrasound in Obstetrics and Gynecology.<\/jats:p><\/jats:sec>","DOI":"10.1002\/uog.24778","type":"journal-article","created":{"date-parts":[[2021,9,20]],"date-time":"2021-09-20T09:39:05Z","timestamp":1632130745000},"page":"793-798","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Expected\u2010value bias in mid\u2010trimester preterm birth screening"],"prefix":"10.1002","volume":"59","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7631-4810","authenticated-orcid":false,"given":"A.","family":"Aiartzaguena","sequence":"first","affiliation":[{"name":"Hospital Universitario Cruces, Biocruces Bizkaia Health Research Institute UPV\/EHU  Bizkaia Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A.","family":"Del Campo","sequence":"additional","affiliation":[{"name":"Hospital Universitario Cruces, Biocruces Bizkaia Health Research Institute UPV\/EHU  Bizkaia Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"I.","family":"Melchor","sequence":"additional","affiliation":[{"name":"Hospital Universitario Cruces, Biocruces Bizkaia Health Research Institute UPV\/EHU  Bizkaia Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J.","family":"Guti\u00e9rrez","sequence":"additional","affiliation":[{"name":"Hospital Universitario Cruces, Biocruces Bizkaia Health Research Institute UPV\/EHU  Bizkaia Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5805-419X","authenticated-orcid":false,"given":"J. C.","family":"Melchor","sequence":"additional","affiliation":[{"name":"Hospital Universitario Cruces, Biocruces Bizkaia Health Research Institute UPV\/EHU  Bizkaia Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9923-9403","authenticated-orcid":false,"given":"J.","family":"Burgos","sequence":"additional","affiliation":[{"name":"Hospital Universitario Cruces, Biocruces Bizkaia Health Research Institute UPV\/EHU  Bizkaia Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2022,6]]},"reference":[{"key":"e_1_2_7_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.tjog.2017.12.006"},{"key":"e_1_2_7_3_1","volume-title":"Experimentation: An Introduction to Measurement Theory and Experiment Design","author":"Baird DC","year":"1995"},{"key":"e_1_2_7_4_1","volume-title":"An Introduction to Error Analysis. The study of uncertainties in physical measurements","author":"Taylor JR","year":"1997"},{"key":"e_1_2_7_5_1","doi-asserted-by":"publisher","DOI":"10.1136\/ebmed-2017-110884"},{"key":"e_1_2_7_6_1","doi-asserted-by":"publisher","DOI":"10.1136\/bmj.321.7259.504"},{"key":"e_1_2_7_7_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajog.2017.11.576"},{"key":"e_1_2_7_8_1","unstructured":"CFEF.org: [L'article du MOIS: Les \u00e9tudes flash du CFEF].http:\/\/www.cfef.org\/article\u2010archive.php?ref=9\/."},{"key":"e_1_2_7_9_1","unstructured":"CFEF.org: [\u00c9tude flash].https:\/\/www.cfef.org\/etudes_flash\/."},{"key":"e_1_2_7_10_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.14742"},{"key":"e_1_2_7_11_1","doi-asserted-by":"publisher","DOI":"10.1002\/pd.2640"},{"key":"e_1_2_7_12_1","unstructured":"Perinatalquality.org:Cervical Length Education and Review Program.https:\/\/clear.perinatalquality.org\/default.aspx\/."},{"key":"e_1_2_7_13_1","doi-asserted-by":"publisher","DOI":"10.1097\/AOG.0000000000001820"},{"key":"e_1_2_7_14_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.21929"},{"key":"e_1_2_7_15_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.20232"},{"key":"e_1_2_7_16_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.20102"},{"key":"e_1_2_7_17_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.5331"},{"key":"e_1_2_7_18_1","doi-asserted-by":"publisher","DOI":"10.1159\/000341264"},{"key":"e_1_2_7_19_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.15894"},{"key":"e_1_2_7_20_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.12413"},{"key":"e_1_2_7_21_1","doi-asserted-by":"publisher","DOI":"10.3109\/14767058.2015.1051956"},{"key":"e_1_2_7_22_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.15866"},{"key":"e_1_2_7_23_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.17223"},{"key":"e_1_2_7_24_1","doi-asserted-by":"publisher","DOI":"10.1002\/pd.2417"},{"key":"e_1_2_7_25_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajogmf.2019.100035"},{"key":"e_1_2_7_26_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.18811"},{"key":"e_1_2_7_27_1","doi-asserted-by":"publisher","DOI":"10.1111\/ajo.12984"}],"container-title":["Ultrasound in Obstetrics &amp; Gynecology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/uog.24778","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1002\/uog.24778","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/obgyn.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/uog.24778","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,5,19]],"date-time":"2025-05-19T20:21:54Z","timestamp":1747686114000},"score":1,"resource":{"primary":{"URL":"https:\/\/obgyn.onlinelibrary.wiley.com\/doi\/10.1002\/uog.24778"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,6]]},"references-count":26,"journal-issue":{"issue":"6","published-print":{"date-parts":[[2022,6]]}},"alternative-id":["10.1002\/uog.24778"],"URL":"https:\/\/doi.org\/10.1002\/uog.24778","archive":["Portico"],"relation":{},"ISSN":["0960-7692","1469-0705"],"issn-type":[{"value":"0960-7692","type":"print"},{"value":"1469-0705","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,6]]},"assertion":[{"value":"2021-04-29","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2021-09-06","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2022-06-01","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}