{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T21:23:53Z","timestamp":1784755433424,"version":"3.55.0"},"reference-count":27,"publisher":"Elsevier BV","issue":"6","license":[{"start":{"date-parts":[[2026,6,1]],"date-time":"2026-06-01T00:00:00Z","timestamp":1780272000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.elsevier.com\/tdm\/userlicense\/1.0\/"},{"start":{"date-parts":[[2026,6,1]],"date-time":"2026-06-01T00:00:00Z","timestamp":1780272000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.elsevier.com\/legal\/tdmrep-license"},{"start":{"date-parts":[[2026,3,9]],"date-time":"2026-03-09T00:00:00Z","timestamp":1773014400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["jthjournal.org","elsevier.com","sciencedirect.com"],"crossmark-restriction":true},"short-container-title":["Journal of Thrombosis and Haemostasis"],"published-print":{"date-parts":[[2026,6]]},"DOI":"10.1016\/j.jtha.2026.01.029","type":"journal-article","created":{"date-parts":[[2026,3,4]],"date-time":"2026-03-04T07:52:02Z","timestamp":1772610722000},"page":"2087-2095","update-policy":"https:\/\/doi.org\/10.1016\/elsevier_cm_policy","source":"Crossref","is-referenced-by-count":1,"title":["Contrary to current guidance, antenatal factor IX levels increase in female carriers of hemophilia B"],"prefix":"10.1016","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5172-0046","authenticated-orcid":false,"given":"Claire","family":"Kelly","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Janet","family":"Cleary","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Catriona","family":"Keenan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Isabelle","family":"Delachapelle","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leona","family":"Connolly","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mary","family":"Byrne","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mairead","family":"O\u2019Donovan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Niamh M.","family":"O\u2019Connell","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"James S.","family":"O\u2019Donnell","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kevin","family":"Ryan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2999-4216","authenticated-orcid":false,"given":"Michelle","family":"Lavin","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"78","reference":[{"key":"10.1016\/j.jtha.2026.01.029_bib1","doi-asserted-by":"crossref","first-page":"1883","DOI":"10.1111\/jth.15397","article-title":"A new hemophilia carrier nomenclature to define hemophilia in women and girls: communication from the SSC of the ISTH","volume":"19","author":"van Galen","year":"2021","journal-title":"J Thromb Haemost"},{"key":"10.1016\/j.jtha.2026.01.029_bib2","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1055\/s-0041-1723797","article-title":"Current challenges in the peripartum management of women with von Willebrand disease","volume":"47","author":"Byrne","year":"2021","journal-title":"Semin Thromb Hemost"},{"key":"10.1016\/j.jtha.2026.01.029_bib3","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1016\/j.bcmd.2016.11.012","article-title":"Developmental hemostasis: a lifespan from neonates and pregnancy to the young and elderly adult in a European white population","volume":"67","author":"Nowak-G\u00f6ttl","year":"2017","journal-title":"Blood Cells Mol Dis"},{"key":"10.1016\/j.jtha.2026.01.029_bib4","first-page":"483","article-title":"Pregnancy and delivery in a woman with hemophilia B","volume":"46","author":"Rust","year":"1975","journal-title":"Obstet Gynecol"},{"key":"10.1016\/j.jtha.2026.01.029_bib5","first-page":"87","article-title":"Factor IX levels during pregnancy in a women with hemophilia B","volume":"11","author":"Briet","year":"1982","journal-title":"Haemostasis"},{"issue":"3 Suppl","key":"10.1016\/j.jtha.2026.01.029_bib6","first-page":"23s","article-title":"Obstetric care of the affected carrier of hemophilia B","volume":"62","author":"Seeds","year":"1983","journal-title":"Obstet Gynecol"},{"key":"10.1016\/j.jtha.2026.01.029_bib7","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1002\/ajh.2830240215","article-title":"Discordance in a pair of identical twin carriers of factor IX deficiency","volume":"24","author":"Kitchens","year":"1987","journal-title":"Am J Hematol"},{"key":"10.1016\/j.jtha.2026.01.029_bib8","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1016\/0020-7292(93)90210-N","article-title":"An unusual complication in a gravida with factor IX deficiency: case report with review of the literature","volume":"41","author":"Guy","year":"1993","journal-title":"Int J Gynaecol Obstet"},{"key":"10.1016\/j.jtha.2026.01.029_bib9","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1111\/j.1365-2516.2007.01561.x","article-title":"Pregnancy in carriers of haemophilia","volume":"14","author":"Chi","year":"2008","journal-title":"Haemophilia"},{"key":"10.1016\/j.jtha.2026.01.029_bib10","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1016\/j.ijoa.2011.04.003","article-title":"Labor and delivery in a patient with hemophilia B","volume":"20","author":"Przkora","year":"2011","journal-title":"Int J Obstet Anesth"},{"key":"10.1016\/j.jtha.2026.01.029_bib11","doi-asserted-by":"crossref","first-page":"e256","DOI":"10.1111\/hae.13521","article-title":"Postpartum haemorrhage in an unselected cohort of carriers of haemophilia","volume":"24","author":"Zwagemaker","year":"2018","journal-title":"Haemophilia"},{"key":"10.1016\/j.jtha.2026.01.029_bib12","doi-asserted-by":"crossref","first-page":"e261","DOI":"10.1111\/bjh.16887","article-title":"Pregnancy outcomes in female carriers of haemophilia B Leyden","volume":"190","author":"Gandhi","year":"2020","journal-title":"Br J Haematol"},{"key":"10.1016\/j.jtha.2026.01.029_bib13","doi-asserted-by":"crossref","first-page":"9759","DOI":"10.1080\/14767058.2022.2051699","article-title":"Management and outcomes of mild hemophiliacs and hemophilia carriers during pregnancy and peripartum period: a hemophilia treatment center experience in the United States","volume":"35","author":"Lim","year":"2022","journal-title":"J Matern Fetal Neonatal Med"},{"key":"10.1016\/j.jtha.2026.01.029_bib14","first-page":"e193","article-title":"on behalf of the Royal College of Obstetricians and Gynaecologists. Management of inherited bleeding disorders in pregnancy: Green-top Guideline No. 71 (joint with UKHCDO)","volume":"124","author":"Pavord","year":"2017","journal-title":"BJOG"},{"key":"10.1016\/j.jtha.2026.01.029_bib15","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1111\/hae.14046","article-title":"WFH Guidelines for the Management of Hemophilia, 3rd edition","volume":"26","author":"Srivastava","year":"2020","journal-title":"Haemophilia"},{"key":"10.1016\/j.jtha.2026.01.029_bib16","doi-asserted-by":"crossref","first-page":"717","DOI":"10.1111\/j.1365-2516.2008.01765.x","article-title":"Mutation analysis of haemophilia B in the Irish population: increased prevalence caused by founder effect","volume":"14","author":"Jenkins","year":"2008","journal-title":"Haemophilia"},{"key":"10.1016\/j.jtha.2026.01.029_bib17","doi-asserted-by":"crossref","first-page":"e498","DOI":"10.1111\/hae.12761","article-title":"Age-related factor IX correction in symptomatic female carriers with haemophilia B Leyden","volume":"21","author":"Lavin","year":"2015","journal-title":"Haemophilia"},{"key":"10.1016\/j.jtha.2026.01.029_bib18","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1186\/s13073-024-01421-5","article-title":"HGVS Nomenclature 2024: improvements to community engagement, usability, and computability","volume":"16","author":"Hart","year":"2024","journal-title":"Genome Med"},{"key":"10.1016\/j.jtha.2026.01.029_bib19","doi-asserted-by":"crossref","first-page":"288","DOI":"10.1007\/s00540-021-02911-1","article-title":"Delivery and neuraxial technique outcomes in patients with hemophilia and in hemophilia carriers: a systematic review","volume":"35","author":"Togioka","year":"2021","journal-title":"J Anesth"},{"key":"10.1016\/j.jtha.2026.01.029_bib20","doi-asserted-by":"crossref","first-page":"7921","DOI":"10.1073\/pnas.0902191106","article-title":"An age-related homeostasis mechanism is essential for spontaneous amelioration of hemophilia B Leyden","volume":"106","author":"Kurachi","year":"2009","journal-title":"Proc Natl Acad Sci U S A"},{"key":"10.1016\/j.jtha.2026.01.029_bib21","series-title":"WHO guideline on use of ferritin concentrations to assess iron status in individuals and populations (Executive summary)","year":"2020"},{"key":"10.1016\/j.jtha.2026.01.029_bib22","doi-asserted-by":"crossref","first-page":"784","DOI":"10.1002\/ajh.25800","article-title":"The benefits of iron supplementation following blood donation vary with baseline iron status","volume":"95","author":"Mast","year":"2020","journal-title":"Am J Hematol"},{"key":"10.1016\/j.jtha.2026.01.029_bib23","doi-asserted-by":"crossref","first-page":"993","DOI":"10.1002\/ijgo.70529","article-title":"FIGO good practice recommendations on anemia in pregnancy, to reduce the incidence and impact of postpartum hemorrhage (PPH)","volume":"171","author":"Ubom","year":"2025","journal-title":"Int J Gynaecol Obstet"},{"key":"10.1016\/j.jtha.2026.01.029_bib24","doi-asserted-by":"crossref","first-page":"2629","DOI":"10.1016\/j.jtha.2024.05.026","article-title":"International Society on Thrombosis and Haemostasis clinical practice guideline for treatment of congenital hemophilia A and B based on the Grading of Recommendations Assessment, Development, and Evaluation methodology","volume":"22","author":"Rezende","year":"2024","journal-title":"J Thromb Haemost"},{"key":"10.1016\/j.jtha.2026.01.029_bib25","doi-asserted-by":"crossref","first-page":"801","DOI":"10.1136\/bmj.1.5595.801","article-title":"Increased factor IX levels in puerperium during administration of diethylstilboestrol","volume":"1","author":"Daniel","year":"1968","journal-title":"BMJ"},{"key":"10.1016\/j.jtha.2026.01.029_bib26","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1111\/j.1365-2141.2007.06912.x","article-title":"Identification and functional characterization of a polymorphic oestrogen response element in the human coagulation factor IX gene promoter","volume":"140","author":"Adams","year":"2008","journal-title":"Br J Haematol"},{"issue":"Suppl 1","key":"10.1016\/j.jtha.2026.01.029_bib27","doi-asserted-by":"crossref","first-page":"1208","DOI":"10.1182\/blood-2024-207237","article-title":"The influence of postpartum hemorrhage on the quality of life among pregnant hemophilia A and B carriers: the Pregnancy and Inherited Bleeding Disorders Study (PRIDES)","volume":"144","author":"de Vaan","year":"2024","journal-title":"Blood"}],"container-title":["Journal of Thrombosis and Haemostasis"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.elsevier.com\/content\/article\/PII:S1538783626001170?httpAccept=text\/xml","content-type":"text\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/api.elsevier.com\/content\/article\/PII:S1538783626001170?httpAccept=text\/plain","content-type":"text\/plain","content-version":"vor","intended-application":"text-mining"}],"deposited":{"date-parts":[[2026,6,4]],"date-time":"2026-06-04T12:04:58Z","timestamp":1780574698000},"score":1,"resource":{"primary":{"URL":"https:\/\/linkinghub.elsevier.com\/retrieve\/pii\/S1538783626001170"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6]]},"references-count":27,"journal-issue":{"issue":"6","published-print":{"date-parts":[[2026,6]]}},"alternative-id":["S1538783626001170"],"URL":"https:\/\/doi.org\/10.1016\/j.jtha.2026.01.029","relation":{},"ISSN":["1538-7836"],"issn-type":[{"value":"1538-7836","type":"print"}],"subject":[],"published":{"date-parts":[[2026,6]]},"assertion":[{"value":"Elsevier","name":"publisher","label":"This article is maintained by"},{"value":"Contrary to current guidance, antenatal factor IX levels increase in female carriers of hemophilia B","name":"articletitle","label":"Article Title"},{"value":"Journal of Thrombosis and Haemostasis","name":"journaltitle","label":"Journal Title"},{"value":"https:\/\/doi.org\/10.1016\/j.jtha.2026.01.029","name":"articlelink","label":"CrossRef DOI link to publisher maintained version"},{"value":"article","name":"content_type","label":"Content Type"},{"value":"\u00a9 2026 The Authors. Published by Elsevier Inc. on behalf of International Society on Thrombosis and Haemostasis.","name":"copyright","label":"Copyright"}]}}