{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T00:44:19Z","timestamp":1787013859607,"version":"build-2736575974"},"reference-count":30,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[2021,11,15]],"date-time":"2021-11-15T00:00:00Z","timestamp":1636934400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004212","name":"P\u00e4ivikki ja Sakari Sohlbergin S\u00e4\u00e4ti\u00f6","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100004212","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["obgyn.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Acta Obstet Gynecol Scand"],"published-print":{"date-parts":[[2022,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Although the perinatal mortality of monochorionic twins has been reported to be higher, the role of chorionicity is debated and data from Finland are still lacking. To examine the effect of chorionicity on the main outcome measures, perinatal and neonatal mortality and neonatal morbidity of Finnish twins, a comprehensive population\u2010based historical cohort study was performed at Helsinki University Hospitals.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Material and methods<\/jats:title>\n                    <jats:p>All 1034 dichorionic and monochorionic\u2010diamniotic twin pregnancies managed at Helsinki University Hospital area during 2006, 2010, 2014 and 2018 were collected from patient databases. Information on chorionicity was retrieved from ultrasound reports and all relevant clinical information from patient records. Differences in perinatal and neonatal mortality and neonatal morbidity were analyzed by performing group comparisons between the twins and chorionicity. The role of chorionicity was also assessed in logistic regression analyses.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      There were 1034 dichorionic\u2010diamniotic (DCDA,\n                      <jats:italic>n<\/jats:italic>\n                      \u00a0=\u00a0789, 76.3%, 95% confidence interval [CI] 73.6\u201378.9) and monochorionic\u2010diamniotic (MCDA,\n                      <jats:italic>n\u00a0<\/jats:italic>\n                      =\u00a0245, 23.7%, 95% CI 21.4\u201326.0) twin pregnancies during the studied years. Most (\n                      <jats:italic>n<\/jats:italic>\n                      \u00a0=\u00a0580, 56.1%, 95% CI 52.8\u201359.2) twins were born at term, but 151 (61.6%, 95% CI 55.8\u201367.3) of MCDA twins were preterm and had lower birthweight and Apgar scores and higher risk of death of one twin. Perinatal and neonatal mortality did not differ between twins A and B, but the immediate outcome of twin B was worse, with lower arterial pH and Apgar scores and increased need of neonatal intensive care unit treatment.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Chorionicity contributes to the perinatal and neonatal outcome in favor of dichorionic twins. This disadvantage of MCDA twinning is likely explained by earlier gestational age at birth and inequal placental sharing. Irrespective of chorionicity, twin B faces more complications.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1111\/aogs.14285","type":"journal-article","created":{"date-parts":[[2021,11,15]],"date-time":"2021-11-15T09:20:02Z","timestamp":1636968002000},"page":"153-162","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":23,"title":["Perinatal outcome of dichorionic and monochorionic\u2010diamniotic Finnish twins: a historical cohort study"],"prefix":"10.1111","volume":"101","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7840-0870","authenticated-orcid":false,"given":"Annu\u2010Riikka S.","family":"Rissanen","sequence":"first","affiliation":[{"name":"Obstetrics and Gynecology University of Helsinki Helsinki Finland"},{"name":"Obstetrics and Gynecology Welfare Districs of P\u00e4ij\u00e4t\u2010H\u00e4me Lahti Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8254-7525","authenticated-orcid":false,"given":"Mika","family":"Gissler","sequence":"additional","affiliation":[{"name":"Finnish Institute for Health and Welfare Helsinki Finland"},{"name":"Department of Molecular Medicine and Surgery Karolinska Institute Stockholm Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Irmeli K.","family":"Nupponen","sequence":"additional","affiliation":[{"name":"Children\u2019s Hospital University of Helsinki and Helsinki University Hospital Helsinki Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mika E.","family":"Nuutila","sequence":"additional","affiliation":[{"name":"Obstetrics and Gynecology University of Helsinki and Helsinki University Hospital Helsinki Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7459-2032","authenticated-orcid":false,"given":"Riina M.","family":"Jernman","sequence":"additional","affiliation":[{"name":"Obstetrics and Gynecology University of Helsinki and Helsinki University Hospital Helsinki Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2021,11,15]]},"reference":[{"key":"e_1_2_10_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ogrm.2007.07.011"},{"key":"e_1_2_10_3_1","doi-asserted-by":"publisher","DOI":"10.1097\/AOG.0000000000001643"},{"key":"e_1_2_10_4_1","doi-asserted-by":"publisher","DOI":"10.12927\/hcq.2011.22646"},{"key":"e_1_2_10_5_1","doi-asserted-by":"publisher","DOI":"10.1530\/REP-08-0206"},{"key":"e_1_2_10_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajog.2016.10.005"},{"key":"e_1_2_10_7_1","doi-asserted-by":"publisher","DOI":"10.5468\/ogs.2017.60.5.421"},{"key":"e_1_2_10_8_1","doi-asserted-by":"publisher","DOI":"10.1136\/bmj.i4353"},{"key":"e_1_2_10_9_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.siny.2012.01.012"},{"key":"e_1_2_10_10_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.earlhumdev.2018.11.005"},{"key":"e_1_2_10_11_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-0528.2007.01556.x"},{"key":"e_1_2_10_12_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.3918"},{"key":"e_1_2_10_13_1","doi-asserted-by":"publisher","DOI":"10.1186\/s12884-019-2670-3"},{"key":"e_1_2_10_14_1","doi-asserted-by":"publisher","DOI":"10.1097\/01.AOG.0000227747.37184.0a"},{"key":"e_1_2_10_15_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.12412"},{"key":"e_1_2_10_16_1","unstructured":"Euro\u2010Peristat Project.European Perinatal Health Report. 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