{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T02:00:33Z","timestamp":1785463233603,"version":"3.56.0"},"reference-count":26,"publisher":"Wiley","issue":"3","license":[{"start":{"date-parts":[[2025,12,22]],"date-time":"2025-12-22T00:00:00Z","timestamp":1766361600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2025,12,22]],"date-time":"2025-12-22T00:00:00Z","timestamp":1766361600000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["obgyn.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Intl J Gynecology &amp;amp; Obste"],"published-print":{"date-parts":[[2026,6]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To quantify how five altitude\u2010adjustment algorithms affect anemia prevalence at 3560\u2009m and to evaluate diagnostic agreement.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We conducted a retrospective, registry\u2010based cross\u2010sectional study of 10\u2009660 pregnant women receiving antenatal care in Shannan, China (3560\u2009m) from January 2022 to December 2024. Each woman contributed one hemoglobin (Hb) measurement, which was assigned to a trimester by gestational week at sampling. Observed Hb values were adjusted using five algorithms (WHO 2024, WHO 2011, Centers for Disease Control and Prevention [CDC], Dirren, Dallman). Anemia thresholds were &lt;110\u2009g\/L for early and late and &lt;105\u2009g\/L for mid\u2010pregnancy under WHO\u20102024; for the other algorithms, &lt;110\u2009g\/L across trimesters. Outcomes included overall and trimester\u2010specific prevalence and diagnostic agreement quantified by Cohen's \u03ba.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Mean observed Hb decreased from 141.1\u2009g\/L in early pregnancy to 117.7\u2009g\/L in late pregnancy. Unadjusted anemia prevalence was 20.7%. After altitude adjustment, prevalence estimates were 69.3% (WHO 2024), 78.2% (WHO 2011\/CDC), 52.9% (Dallman), and 82.9% (Dirren). Across algorithms, prevalence increased with advancing gestation. Agreement was perfect for WHO 2011 versus CDC (\n                      <jats:italic>\u03ba<\/jats:italic>\n                      \u2009=\u20091.000), moderate for WHO 2024 versus CDC (\n                      <jats:italic>\u03ba<\/jats:italic>\n                      \u2009=\u20090.773), and fair for Dirren versus Dallman (\n                      <jats:italic>\u03ba<\/jats:italic>\n                      \u2009=\u20090.376).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Altitude adjustment increased estimated anemia prevalence by up to four\u2010fold at 3560\u2009m in China. Algorithms derived from non\u2010high\u2010altitude populations may misclassify anemia in these settings. Population\u2010tailored standards that incorporate altitude and trimester are warranted to improve screening accuracy and guide interventions.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1002\/ijgo.70766","type":"journal-article","created":{"date-parts":[[2025,12,22]],"date-time":"2025-12-22T11:29:53Z","timestamp":1766402993000},"page":"1496-1502","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Prevalence of anemia among high\u2010altitude pregnant women in Shannan, China, and evaluation of altitude\u2010adjustment methods: A cross\u2010sectional study"],"prefix":"10.1002","volume":"173","author":[{"given":"Dongmei","family":"Cao","sequence":"first","affiliation":[{"name":"Department of Obstetrics Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology  Wuhan China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-8936-501X","authenticated-orcid":false,"given":"Huaqi","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Public Health Tongji Medical College, Huazhong University of Science &amp; Technology  Wuhan China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gangzu","family":"Zhuoma","sequence":"additional","affiliation":[{"name":"Department of Obstetrics Shannan Maternal and Child Health Hospital  Shannan China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-9672-0541","authenticated-orcid":false,"given":"Quan","family":"Gan","sequence":"additional","affiliation":[{"name":"School of Public Health Tongji Medical College, Huazhong University of Science &amp; Technology  Wuhan China"},{"name":"Department of Critical Care Medicine Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology  Wuhan China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2025,12,22]]},"reference":[{"key":"e_1_2_12_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/S2352-3026(23)00160-6"},{"key":"e_1_2_12_3_1","doi-asserted-by":"publisher","DOI":"10.1016\/S2214-109X(22)00084-5"},{"key":"e_1_2_12_4_1","doi-asserted-by":"publisher","DOI":"10.1186\/s12889-024-18610-x"},{"key":"e_1_2_12_5_1","doi-asserted-by":"publisher","DOI":"10.3390\/nu16121854"},{"key":"e_1_2_12_6_1","unstructured":"Central Committee of the Communist Party of China; State Council of the People's Republic of China.Healthy China 2030 Planning Outline. State Council Gazette 322016Accessed September 7 2025.http:\/\/www.gov.cn\/gongbao\/content\/2016\/content_5133024.htm"},{"key":"e_1_2_12_7_1","volume-title":"National Nutrition Plan 2017\u20132030","author":"State Council of China","year":"2017"},{"key":"e_1_2_12_8_1","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.2403309121"},{"key":"e_1_2_12_9_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-022-26868-7"},{"key":"e_1_2_12_10_1","doi-asserted-by":"publisher","DOI":"10.1002\/ajh.24932"},{"key":"e_1_2_12_11_1","doi-asserted-by":"publisher","DOI":"10.1186\/1471-2458-9-336"},{"key":"e_1_2_12_12_1","doi-asserted-by":"publisher","DOI":"10.1111\/nyas.14136"},{"key":"e_1_2_12_13_1","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0405949101"},{"key":"e_1_2_12_14_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.1189406"},{"key":"e_1_2_12_15_1","volume-title":"Guideline on Hemoglobin Cut\u2010Offs to Define Anaemia in Individuals and Populations","author":"World Health Organization","year":"2024"},{"issue":"1","key":"e_1_2_12_16_1","article-title":"Diagnosis and treatment of iron deficiency and iron\u2010deficiency anaemia in pregnancy","volume":"17","author":"Perinatal Medicine Branch of Chinese Medical Association","year":"2014","journal-title":"Chin J Perinat Med"},{"key":"e_1_2_12_17_1","volume-title":"Hemoglobin Concentrations for the Diagnosis of Anaemia and Assessment of Severity","author":"World Health Organization","year":"2011"},{"key":"e_1_2_12_18_1","unstructured":"Centers for Disease Control and Prevention.Altitude hemoglobin curve and CDC anaemia criteria (altitude adjustment).1995Accessed September 7 2025.https:\/\/www.cdc.gov\/mmwr\/preview\/mmwrhtml\/00001405.htm"},{"key":"e_1_2_12_19_1","first-page":"625","article-title":"Altitude correction for hemoglobin","volume":"48","author":"Dirren H","year":"1994","journal-title":"Eur J Clin Nutr"},{"key":"e_1_2_12_20_1","doi-asserted-by":"publisher","DOI":"10.1093\/ajcn\/33.1.86"},{"key":"e_1_2_12_21_1","doi-asserted-by":"publisher","DOI":"10.7620\/zgfybj.j.issn.1001-4411.2017.20.16"},{"issue":"3","key":"e_1_2_12_22_1","first-page":"161","article-title":"Hemoglobin levels in late pregnancy and their association with pregnancy outcomes among Tibetan agro\u2010pastoral women at high altitude","volume":"25","author":"Han ZY","year":"2022","journal-title":"Chin J Perinat Med"},{"key":"e_1_2_12_23_1","doi-asserted-by":"publisher","DOI":"10.1186\/s12884-020-02870-7"},{"key":"e_1_2_12_24_1","doi-asserted-by":"publisher","DOI":"10.1590\/S1020-49891999001100004"},{"key":"e_1_2_12_25_1","doi-asserted-by":"publisher","DOI":"10.1265\/ehpm.22-00040"},{"key":"e_1_2_12_26_1","first-page":"818","article-title":"Down\u2010regulation of EPAS1 transcription and genetic adaptation of Tibetans to high\u2010altitude hypoxia","volume":"34","author":"Peng Y","year":"2017","journal-title":"Mol Biol Evol"},{"key":"e_1_2_12_27_1","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00321.2017"}],"container-title":["International Journal of Gynecology &amp; Obstetrics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/obgyn.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/ijgo.70766","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/obgyn.onlinelibrary.wiley.com\/doi\/full-xml\/10.1002\/ijgo.70766","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/obgyn.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/ijgo.70766","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T01:41:47Z","timestamp":1785462107000},"score":1,"resource":{"primary":{"URL":"https:\/\/obgyn.onlinelibrary.wiley.com\/doi\/10.1002\/ijgo.70766"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,12,22]]},"references-count":26,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2026,6]]}},"alternative-id":["10.1002\/ijgo.70766"],"URL":"https:\/\/doi.org\/10.1002\/ijgo.70766","archive":["Portico"],"relation":{},"ISSN":["0020-7292","1879-3479"],"issn-type":[{"value":"0020-7292","type":"print"},{"value":"1879-3479","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,12,22]]},"assertion":[{"value":"2025-09-23","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-12-08","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-12-22","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}