{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,24]],"date-time":"2026-06-24T22:37:05Z","timestamp":1782340625013,"version":"3.54.5"},"reference-count":27,"publisher":"Wiley","issue":"4","license":[{"start":{"date-parts":[[2024,4,1]],"date-time":"2024-04-01T00:00:00Z","timestamp":1711929600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["obgyn.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Ultrasound in Obstet &amp;amp; Gyne"],"published-print":{"date-parts":[[2024,4]]},"abstract":"<jats:title>ABSTRACT<\/jats:title><jats:sec><jats:title>Objectives<\/jats:title><jats:p>To perform a nationwide study of quadrichorionic quadriamniotic (QCQA) quadruplet pregnancies and to compare the pregnancy outcome in those undergoing fetal reduction with non\u2010reduced quadruplets and dichorionic diamniotic (DCDA) twin pregnancies from the same time period.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>This was a retrospective Danish national register\u2010based study performed using data from the national Danish Fetal Medicine Database, which included all QCQA quadruplets and all non\u2010reduced DCDA twin pregnancies with an estimated due date between 2008 and 2018. The primary outcome measure was a composite of adverse pregnancy outcomes, including pregnancy loss or intrauterine death of one or more fetuses. Secondary outcomes included gestational age at delivery, the number of liveborn children, preterm delivery before 28, 32 and 37\u2009gestational weeks and birth weight. Data on pregnancy complications and baseline characteristics were also recorded. Outcomes were compared between reduced and non\u2010reduced quadruplet pregnancies, and between DCDA pregnancies and quadruplet pregnancies reduced to twins. A systematic literature search was performed to describe and compare previous results with our findings.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Included in the study were 33 QCQA quadruplet pregnancies, including three (9.1%) non\u2010reduced pregnancies, 28 (84.8%) that were reduced to twin pregnancy and fewer than three (6.1%) that were reduced to singleton pregnancy, as well as 9563 DCDA twin pregnancies. Overall, the rate of adverse pregnancy outcome was highest in non\u2010reduced quadruplets (66.7%); it was 50% in quadruplets reduced to singletons and 10.7% in quadruplets reduced to twins. The proportion of liveborn infants overall was 91.1% of the total number expected to be liveborn in quadruplet pregnancies reduced to twins. This was statistically significantly different from 97.6% in non\u2010reduced dichorionic twins (<jats:italic>P<\/jats:italic>\u2009=\u20090.004), and considerably higher than 58.3% in non\u2010reduced quadruplets. The rates of preterm delivery &lt;\u200928, &lt;\u200932 and &lt;\u200937\u2009weeks were decreased in quadruplets reduced to twins compared with those in non\u2010reduced quadruplet pregnancies. Quadruplets reduced to twins did not achieve equivalent pregnancy outcomes to those of DCDA twins.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>This national study of QCQA quadruplets has shown that multifetal pregnancy reduction improves pregnancy outcome, including a decreased rate of preterm delivery and higher proportion of liveborn children. \u00a9 2023 The Authors. <jats:italic>Ultrasound in Obstetrics &amp; Gynecology<\/jats:italic> published by John Wiley &amp; Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.<\/jats:p><\/jats:sec>","DOI":"10.1002\/uog.27497","type":"journal-article","created":{"date-parts":[[2023,9,25]],"date-time":"2023-09-25T05:48:03Z","timestamp":1695620883000},"page":"514-521","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Quadruplet pregnancy outcome with and without fetal reduction: Danish national cohort study (2008\u20132018) and comparison with dichorionic twins"],"prefix":"10.1002","volume":"63","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-8974-824X","authenticated-orcid":false,"given":"M. K.","family":"Rasmussen","sequence":"first","affiliation":[{"name":"Department of Obstetrics, Center for Fetal Medicine and Ultrasound Copenhagen University Hospital Rigshospitalet  Copenhagen Denmark"},{"name":"Department of Clinical Medicine, Faculty of Health and Medical Sciences University of Copenhagen  Copenhagen Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S. E.","family":"Kristensen","sequence":"additional","affiliation":[{"name":"Department of Obstetrics, Center for Fetal Medicine and Ultrasound Copenhagen University Hospital Rigshospitalet  Copenhagen Denmark"},{"name":"Department of Clinical Medicine, Faculty of Health and Medical Sciences University of Copenhagen  Copenhagen Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C. K.","family":"Ekelund","sequence":"additional","affiliation":[{"name":"Department of Obstetrics, Center for Fetal Medicine and Ultrasound Copenhagen University Hospital Rigshospitalet  Copenhagen Denmark"},{"name":"Department of Clinical Medicine, Faculty of Health and Medical Sciences University of Copenhagen  Copenhagen Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P.","family":"Sandager","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology Center for Fetal Medicine, Aarhus University Hospital  Aarhus Denmark"},{"name":"Center for Fetal Diagnostics Aarhus University Hospital  Aarhus Denmark"},{"name":"Department of Clinical Medicine Aarhus University  Aarhus Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"F. S.","family":"J\u00f8rgensen","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, Fetal Medicine Unit Copenhagen University Hospital Hvidovre  Hvidovre Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"E.","family":"Hoseth","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, Clinic of Ultrasound Aalborg University Hospital  Aalborg Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"L.","family":"Sperling","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, Center for Ultrasound and Pregnancy Odense University Hospital  Odense Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"H. J.","family":"Zingenberg","sequence":"additional","affiliation":[{"name":"Department of Gynecology and Obstetrics Copenhagen University Hospital Herlev  Herlev Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"T. D.","family":"Hjortsh\u00f8j","sequence":"additional","affiliation":[{"name":"Department of Clinical Genetics Copenhagen University Hospital Rigshospitalet  Copenhagen Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K.","family":"Gadsb\u00f8ll","sequence":"additional","affiliation":[{"name":"Department of Obstetrics, Center for Fetal Medicine and Ultrasound Copenhagen University Hospital Rigshospitalet  Copenhagen Denmark"},{"name":"Department of Clinical Medicine, Faculty of Health and Medical Sciences University of Copenhagen  Copenhagen Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A.","family":"Wright","sequence":"additional","affiliation":[{"name":"Institute of Health Research University of Exeter  Exeter UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D.","family":"Wright","sequence":"additional","affiliation":[{"name":"Institute of Health Research University of Exeter  Exeter UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8979-4534","authenticated-orcid":false,"given":"A.","family":"McLennan","sequence":"additional","affiliation":[{"name":"Sydney Ultrasound for Women  Chatswood NSW Australia"},{"name":"Discipline of Obstetrics, Gynecology and Neonatology The University of Sydney  Sydney NSW Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K.","family":"Sundberg","sequence":"additional","affiliation":[{"name":"Department of Obstetrics, Center for Fetal Medicine and Ultrasound Copenhagen University Hospital Rigshospitalet  Copenhagen Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"O. B.","family":"Petersen","sequence":"additional","affiliation":[{"name":"Department of Obstetrics, Center for Fetal Medicine and Ultrasound Copenhagen University Hospital Rigshospitalet  Copenhagen Denmark"},{"name":"Department of Clinical Medicine, Faculty of Health and Medical Sciences University of Copenhagen  Copenhagen Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2024,4]]},"reference":[{"key":"e_1_2_7_2_1","doi-asserted-by":"publisher","DOI":"10.1067\/mob.2001.108074"},{"key":"e_1_2_7_3_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.bpobgyn.2004.04.019"},{"key":"e_1_2_7_4_1","doi-asserted-by":"publisher","DOI":"10.1097\/00001703-200012000-00006"},{"key":"e_1_2_7_5_1","first-page":"663","article-title":"Perinatal Problems in Multiple Births","volume":"107","author":"Dudenhausen JW","year":"2010","journal-title":"Dtsch Arztebl Int"},{"key":"e_1_2_7_6_1","doi-asserted-by":"publisher","DOI":"10.1159\/000059372"},{"key":"e_1_2_7_7_1","doi-asserted-by":"publisher","DOI":"10.1159\/000065382"},{"key":"e_1_2_7_8_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.clp.2005.03.002"},{"key":"e_1_2_7_9_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajog.2008.06.017"},{"key":"e_1_2_7_10_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10654-014-9930-3"},{"key":"e_1_2_7_11_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.19073"},{"key":"e_1_2_7_12_1","doi-asserted-by":"publisher","DOI":"10.1136\/bmj.n160"},{"key":"e_1_2_7_13_1","unstructured":"Group TGW.GRADE handbook for grading quality of evidence and strength of recommendations 2013."},{"key":"e_1_2_7_14_1","unstructured":"Prime MUaE.GRADEpro GDT: GRADEpro Guideline Development Tool (Software).https:\/\/www.gradepro.org."},{"key":"e_1_2_7_15_1","volume-title":"RStudio: Integrated Development for R","author":"RStudio Team","year":"2019"},{"key":"e_1_2_7_16_1","doi-asserted-by":"publisher","DOI":"10.1016\/1071-5576(95)00037-2"},{"key":"e_1_2_7_17_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0015-0282(16)56453-X"},{"key":"e_1_2_7_18_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-0528.1992.tb13734.x"},{"key":"e_1_2_7_19_1","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/deh090"},{"key":"e_1_2_7_20_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00404-016-4145-3"},{"key":"e_1_2_7_21_1","doi-asserted-by":"publisher","DOI":"10.1515\/jpm-2014-0340"},{"key":"e_1_2_7_22_1","doi-asserted-by":"publisher","DOI":"10.1080\/14767050410001728962"},{"key":"e_1_2_7_23_1","doi-asserted-by":"publisher","DOI":"10.1055\/s-0040-1715167"},{"key":"e_1_2_7_24_1","first-page":"603","article-title":"Effect of spontaneous pregnancy reduction on obstetric outcome","volume":"50","author":"Steinkampf MP","year":"2005","journal-title":"J Reprod Med"},{"key":"e_1_2_7_25_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0002-9378(98)70276-5"},{"key":"e_1_2_7_26_1","doi-asserted-by":"publisher","DOI":"10.1159\/000263829"},{"key":"e_1_2_7_27_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0002-9378(96)70666-X"},{"key":"e_1_2_7_28_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0301-2115(99)00153-0"}],"container-title":["Ultrasound in Obstetrics &amp; Gynecology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/obgyn.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/uog.27497","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,4,12]],"date-time":"2024-04-12T12:22:31Z","timestamp":1712924551000},"score":1,"resource":{"primary":{"URL":"https:\/\/obgyn.onlinelibrary.wiley.com\/doi\/10.1002\/uog.27497"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,4]]},"references-count":27,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2024,4]]}},"alternative-id":["10.1002\/uog.27497"],"URL":"https:\/\/doi.org\/10.1002\/uog.27497","archive":["Portico"],"relation":{},"ISSN":["0960-7692","1469-0705"],"issn-type":[{"value":"0960-7692","type":"print"},{"value":"1469-0705","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,4]]},"assertion":[{"value":"2023-05-11","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2023-09-18","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-04-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}