{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,2]],"date-time":"2026-06-02T09:39:19Z","timestamp":1780393159557,"version":"3.54.1"},"reference-count":35,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2025,9,4]],"date-time":"2025-09-04T00:00:00Z","timestamp":1756944000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000925","name":"National Health and Medical Research Council Investigator","doi-asserted-by":"publisher","award":["GNT1174971"],"award-info":[{"award-number":["GNT1174971"]}],"id":[{"id":"10.13039\/501100000925","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000925","name":"National Health and Medical Research Council Investigator","doi-asserted-by":"publisher","award":["GNT1161079"],"award-info":[{"award-number":["GNT1161079"]}],"id":[{"id":"10.13039\/501100000925","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000925","name":"National Health and Medical Research Council Project","doi-asserted-by":"publisher","award":["GNT1174971"],"award-info":[{"award-number":["GNT1174971"]}],"id":[{"id":"10.13039\/501100000925","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000925","name":"National Health and Medical Research Council Project","doi-asserted-by":"publisher","award":["GNT1161079"],"award-info":[{"award-number":["GNT1161079"]}],"id":[{"id":"10.13039\/501100000925","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Flinders Foundation Health Seed","award":["GNT1174971"],"award-info":[{"award-number":["GNT1174971"]}]},{"name":"Flinders Foundation Health Seed","award":["GNT1161079"],"award-info":[{"award-number":["GNT1161079"]}]},{"name":"Matthew Flinders Fellowship","award":["GNT1174971"],"award-info":[{"award-number":["GNT1174971"]}]},{"name":"Matthew Flinders Fellowship","award":["GNT1161079"],"award-info":[{"award-number":["GNT1161079"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Background\/Objectives: Gestational diabetes mellitus (GDM) prevalence in Australia has increased from 5.6% (2010) to 19.3% (2022), coinciding with the introduction of mandatory folic acid (FA) food fortification and increased supplementation. Animal studies show that high FA intake in pregnancy impairs maternal glucose regulation, but the underlying mechanisms are unknown. We investigated whether fortification has altered maternal folate status to increase GDM risk, and whether key hormones that regulate maternal glucose homeostasis are affected following FA fortification. Methods: Serum folate, red cell folate (RCF), prolactin (PRL), human placental lactogen (hPL) and placental growth hormone (GH2) were measured in early pregnancy samples from women enrolled in prospective cohorts: SCOPE (N = 1164; pre-fortification) and STOP (N = 1300; post-fortification). Associations with GDM were assessed. Results: Compared to pre-fortification, women post-fortification had a higher GDM incidence (5.0% vs. 15.2%), serum folate (\u2191 18%), RCF (\u2191 259%), hPL (\u2191 29%), and GH2 (\u2191 13%) concentrations. RCF concentrations above the clinical reference range were found in 57.6% of women post-fortification. Causal mediation analysis suggests that higher RCF contributed to increased GDM risk. Women with RCF excess had 48% more GDM cases, and higher PRL (\u2191 24.2%) and hPL (\u2191 12.7%) levels compared to those within the reference range. Conclusions: Maternal folate excess is likely contributing to the rising prevalence of GDM in Australia. These findings highlight the need to evaluate excess FA\/folate safety in pregnancy, particularly in countries with mandatory fortification. Placental hormones may represent a mechanistic link between excess folate and GDM, warranting further investigation.<\/jats:p>","DOI":"10.3390\/nu17172863","type":"journal-article","created":{"date-parts":[[2025,9,4]],"date-time":"2025-09-04T15:31:21Z","timestamp":1756999881000},"page":"2863","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Maternal Folate Excess, Placental Hormones, and Gestational Diabetes Mellitus: Findings from Prospective Cohorts Before and After Mandatory Folic Acid Food Fortification"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4293-359X","authenticated-orcid":false,"given":"Tanja","family":"Jankovic-Karasoulos","sequence":"first","affiliation":[{"name":"Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, SA 5042, Australia"},{"name":"Robinson Research Institute, School of Biomedicine, The University of Adelaide, North Terrace, Adelaide, SA 5005, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7016-8245","authenticated-orcid":false,"given":"Melanie D.","family":"Smith","sequence":"additional","affiliation":[{"name":"Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, SA 5042, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shalem","family":"Leemaqz","sequence":"additional","affiliation":[{"name":"Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, SA 5042, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Murthy","family":"Mittinty","sequence":"additional","affiliation":[{"name":"Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, SA 5042, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jessica","family":"Williamson","sequence":"additional","affiliation":[{"name":"Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, SA 5042, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4510-3797","authenticated-orcid":false,"given":"Dylan","family":"McCullough","sequence":"additional","affiliation":[{"name":"Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, SA 5042, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4382-0610","authenticated-orcid":false,"given":"Anya L.","family":"Arthurs","sequence":"additional","affiliation":[{"name":"Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, SA 5042, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gustaaf A.","family":"Dekker","sequence":"additional","affiliation":[{"name":"Robinson Research Institute, School of Biomedicine, The University of Adelaide, North Terrace, Adelaide, SA 5005, Australia"},{"name":"Lyell McEwin Hospital, Haydown Road, Elizabeth Vale, SA 5112, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9250-2192","authenticated-orcid":false,"given":"Claire T.","family":"Roberts","sequence":"additional","affiliation":[{"name":"Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, SA 5042, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,9,4]]},"reference":[{"key":"ref_1","unstructured":"AIHW (2025, May 30). 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