{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,2,21]],"date-time":"2025-02-21T07:52:57Z","timestamp":1740124377615,"version":"3.37.3"},"reference-count":31,"publisher":"Wiley","issue":"12","license":[{"start":{"date-parts":[[2015,10,13]],"date-time":"2015-10-13T00:00:00Z","timestamp":1444694400000},"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":["Acta Obstet Gynecol Scand"],"published-print":{"date-parts":[[2015,12]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Introduction<\/jats:title><jats:p>Post\u2010term pregnancies are associated with greater risks for mother and child. Accurate determination of gestational age is necessary for safe care. Female fetuses have been shown to be smaller than males at the time of second\u2010trimester ultrasound (US) examination, leading to underestimation of their age and, potentially, greater impacts of perinatal complications in post\u2010term girls than in post\u2010term boys. The purpose of this study was to investigate the sex ratio of post\u2010term births and differences in perinatal complications (stillbirth, low Apgar score, low birthweight, meconium aspiration and low umbilical artery <jats:styled-content style=\"fixed-case\">pH<\/jats:styled-content>) between post\u2010term boys and girls according to dating method [second\u2010trimester US and last menstrual period (LMP)].<\/jats:p><\/jats:sec><jats:sec><jats:title>Material and methods<\/jats:title><jats:p>Data from gestational week \u226539 to delivery of 13 338 singleton pregnancies between 13 February 2006 and 15 January 2014, were collected from the Obstetrix<jats:sup>\u00ae<\/jats:sup> (Siemens Healthcare) medical records system in Dalarna County, Sweden.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The neonatal male:female ratio increased with gestational age after week 40, as dated by US, reaching 1.69 in gestational week 42. This ratio remained 1 throughout gestation according to dating by the LMP. Post\u2010term pregnancy increased the risks of meconium aspiration and low Apgar score, with no sex difference observed.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>US gestational dating indicated that more boys than girls were born post\u2010term, whereas dating according to LMP revealed no sex difference. These results support the hypothesis that female fetuses are smaller than males, leading to underestimation of their gestational age, at the time of second\u2010trimester US examination.<\/jats:p><\/jats:sec>","DOI":"10.1111\/aogs.12774","type":"journal-article","created":{"date-parts":[[2015,9,18]],"date-time":"2015-09-18T02:26:43Z","timestamp":1442543203000},"page":"1373-1379","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Risk for girls can be adversely affected post\u2010term due to underestimation of gestational age by ultrasound in the second trimester"],"prefix":"10.1111","volume":"94","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2078-3730","authenticated-orcid":false,"given":"Katarina","family":"Bj\u00f6rkman","sequence":"first","affiliation":[{"name":"Department of Obstetrics and Gynecology Falu Hospital Falun Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1907-1071","authenticated-orcid":false,"given":"Jan","family":"Wesstr\u00f6m","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology Falu Hospital Falun Sweden"},{"name":"Center for Clinical Research Dalarna Falun Sweden"},{"name":"Department of Women's and Children's Health Uppsala University Uppsala Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2015,10,13]]},"reference":[{"key":"e_1_2_10_2_1","unstructured":"WHO.2004.International Statistical Classification of Diseases and Related Health Problems 10th revision. Available online at:http:\/\/www.who.int\/classifications\/icd\/ICD-10_2nd_ed_volume2.pdf(accessed August 25 2014)."},{"key":"e_1_2_10_3_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajog.2009.02.034"},{"key":"e_1_2_10_4_1","doi-asserted-by":"publisher","DOI":"10.1080\/00016340600935508"},{"key":"e_1_2_10_5_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajog.2006.10.873"},{"key":"e_1_2_10_6_1","doi-asserted-by":"publisher","DOI":"10.1093\/ije\/28.2.253"},{"key":"e_1_2_10_7_1","doi-asserted-by":"publisher","DOI":"10.1038\/sj.jp.7211560"},{"key":"e_1_2_10_8_1","doi-asserted-by":"publisher","DOI":"10.1097\/GRF.0b013e31804c9b11"},{"key":"e_1_2_10_9_1","first-page":"CD004945","article-title":"Induction of labour for improving birth outcomes for women at or beyond term","volume":"6","author":"G\u00fclmezoglu AM","year":"2012","journal-title":"Cochrane Database Syst Rev"},{"key":"e_1_2_10_10_1","doi-asserted-by":"publisher","DOI":"10.1097\/00006250-200011000-00026"},{"key":"e_1_2_10_11_1","doi-asserted-by":"publisher","DOI":"10.1097\/00006250-200306000-00029"},{"key":"e_1_2_10_12_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1479-828X.2007.00742.x"},{"key":"e_1_2_10_13_1","doi-asserted-by":"publisher","DOI":"10.3109\/00016349409013412"},{"key":"e_1_2_10_14_1","doi-asserted-by":"publisher","DOI":"10.1046\/j.1469-0705.1997.09060367.x"},{"key":"e_1_2_10_15_1","first-page":"175","article-title":"Postterm pregnancy","volume":"4","author":"Galal M","year":"2012","journal-title":"Facts Views Vis Obgyn"},{"key":"e_1_2_10_16_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-0528.1998.tb10253.x"},{"key":"e_1_2_10_17_1","doi-asserted-by":"publisher","DOI":"10.1046\/j.1469-0705.1996.08030178.x"},{"key":"e_1_2_10_18_1","doi-asserted-by":"publisher","DOI":"10.1136\/bmj.281.6250.1253"},{"key":"e_1_2_10_19_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-0528.1988.tb06863.x"},{"key":"e_1_2_10_20_1","doi-asserted-by":"publisher","DOI":"10.1046\/j.1469-0705.1998.11020099.x"},{"key":"e_1_2_10_21_1","doi-asserted-by":"publisher","DOI":"10.1136\/bmj.292.6513.137"},{"key":"e_1_2_10_22_1","doi-asserted-by":"publisher","DOI":"10.3109\/00016347809162700"},{"key":"e_1_2_10_23_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00420-003-0475-0"},{"key":"e_1_2_10_24_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-0528.2008.01678.x"},{"key":"e_1_2_10_25_1","doi-asserted-by":"publisher","DOI":"10.1067\/mob.2002.126645"},{"key":"e_1_2_10_26_1","doi-asserted-by":"publisher","DOI":"10.1046\/j.1469-0705.2002.00855.x"},{"key":"e_1_2_10_27_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.67"},{"key":"e_1_2_10_28_1","doi-asserted-by":"publisher","DOI":"10.1097\/EDE.0b013e3181f3a660"},{"key":"e_1_2_10_29_1","doi-asserted-by":"publisher","DOI":"10.3109\/00016348609161496"},{"key":"e_1_2_10_30_1","doi-asserted-by":"publisher","DOI":"10.1136\/jech.57.8.612"},{"key":"e_1_2_10_31_1","unstructured":"Sveriges Officiella Statistik.2004.Graviditeter f\u00f6rlossningar och nyf\u00f6dda barn. Available online at:http:\/\/www.socialstyrelsen.se\/Lists\/Artikelkatalog\/Attachments\/19627\/2014-12-19.pdf(accessed January 28 2015)."},{"key":"e_1_2_10_32_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1651-2227.1996.tb14164.x"}],"container-title":["Acta Obstetricia et Gynecologica Scandinavica"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1111%2Faogs.12774","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/obgyn.onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/aogs.12774","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,9,24]],"date-time":"2023-09-24T09:55:09Z","timestamp":1695549309000},"score":1,"resource":{"primary":{"URL":"https:\/\/obgyn.onlinelibrary.wiley.com\/doi\/10.1111\/aogs.12774"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,10,13]]},"references-count":31,"journal-issue":{"issue":"12","published-print":{"date-parts":[[2015,12]]}},"alternative-id":["10.1111\/aogs.12774"],"URL":"https:\/\/doi.org\/10.1111\/aogs.12774","archive":["Portico"],"relation":{},"ISSN":["0001-6349","1600-0412"],"issn-type":[{"type":"print","value":"0001-6349"},{"type":"electronic","value":"1600-0412"}],"subject":[],"published":{"date-parts":[[2015,10,13]]},"assertion":[{"value":"2014-09-16","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2015-09-05","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2015-10-13","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}