{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,2]],"date-time":"2026-05-02T02:28:24Z","timestamp":1777688904865,"version":"3.51.4"},"reference-count":41,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,5,30]],"date-time":"2025-05-30T00:00:00Z","timestamp":1748563200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Endocrinol."],"abstract":"<jats:sec><jats:title>Background<\/jats:title><jats:p>Endometrial thickness (EMT) has been confirmed to be associated with pregnancy outcomes after <jats:italic>in vitro<\/jats:italic> fertilization\/intracytoplasmic sperm injection-embryo transfer (IVF\/ICSI-ET), but studies on its relationship with neonatal outcomes are still limited. To our knowledge, this study is the first to investigate the relationship between EMT on the day of hCG trigger and the risk of preterm delivery (PTD) in populations undergoing cleavage-stage embryo transfer and blastocyst transfer, respectively.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>This study was a retrospective cohort study that included singleton live birth cycles of women who underwent autologous IVF\/ICSI-ET at the Reproductive Medicine Center of the First Affiliated Hospital of Zhengzhou University from January 2016 to December 2023. The main study outcome was PTD. The relationship between EMT and PTD was explored using logistic regression in different models. These models were adjusted for baseline characteristics, cycle treatment parameters and maternal pregnancy complications among populations undergoing cleavage-stage embryo and blastocyst transfer.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>In both the unadjusted model and Model I, which was adjusted for baseline characteristics, compared with that in the EMT 7.5\u201312 mm group, the risk of PTD was significantly greater in the EMT &amp;lt; 7.5 mm group and significantly lower in the EMT \u2265 12 mm group (<jats:italic>P<\/jats:italic> &amp;lt; 0.05). In Model II, which was adjusted for all potential confounding factors, including pregnancy conditions, an EMT \u2265 12 mm retained its independent protective effect against PTD in both populations. In contrast, an EMT &amp;lt; 7.5 mm and PTD (OR 2.19; 95% CI, 0.82\u20135.88; P = 0.118) did not significantly correlated in the blastocyst transfer population. However, in patients undergoing cleavage-stage embryo transfer, an EMT &amp;lt; 7.5 mm remained an independent risk factor for PTD (OR 2.14; 95% CI, 1.09\u20134.21; P = 0.027).<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>A thin endometrium on the day of hCG trigger is independently associated with an increased risk of PTD in patients undergoing cleavage-stage embryo transfer but not in those undergoing blastocyst transfer. In contrast, a thick endometrium significantly reduces the risk of PTD in both populations.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fendo.2025.1574123","type":"journal-article","created":{"date-parts":[[2025,5,30]],"date-time":"2025-05-30T04:13:08Z","timestamp":1748578388000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["A thinner endometrium is associated with a greater risk of preterm delivery after fresh cleavage embryo transfer but not after blastocyst transfer: a retrospective cohort study of 11,111 singleton live births"],"prefix":"10.3389","volume":"16","author":[{"given":"Tian","family":"Ye","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Huijuan","family":"Kong","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhiqin","family":"Bu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wenqian","family":"Fan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Linqing","family":"Du","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jing","family":"Li","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yihong","family":"Guo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2025,5,30]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1093\/humupd\/dmad028","article-title":"Declining global fertility rates and the implications for family planning and family building: an IFFS consensus document based on a narrative review of the literature","volume":"30","author":"Fauser","year":"2024","journal-title":"Hum Reprod Update"},{"key":"B2","doi-asserted-by":"publisher","first-page":"87","DOI":"10.1093\/humupd\/dms044","article-title":"Why do singletons conceived after assisted reproduction technology have adverse perinatal outcome? Systematic review and meta-analysis","volume":"19","author":"Pinborg","year":"2013","journal-title":"Hum Reprod Update"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2024.05.168","article-title":"Imprinting disorders in children conceived with assisted reproductive technology in Sweden","volume":"122","author":"Ye","year":"2024","journal-title":"Fertil Steril"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.3389\/fendo.2024.1405550","article-title":"Perinatal complications and neonatal outcomes in in vitro fertilization\/intracytoplasmic sperm injection: a propensity score matching cohort study","volume":"15","author":"Chen","year":"2024","journal-title":"Front Endocrinol (Lausanne)"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2012.09.027","article-title":"Implications of assisted reproductive technologies on term singleton birth weight: an analysis of 25,777 children in the national assisted reproduction registry of Japan","volume":"99","author":"Nakashima","year":"2013","journal-title":"Fertil Steril"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1016\/j.rbmo.2022.01.004","article-title":"Does underlying infertility in natural conception modify the epigenetic control of imprinted genes and transposable elements in newborns","volume":"44","author":"Barberet","year":"2022","journal-title":"Reprod BioMed Online"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1093\/humupd\/dmu011","article-title":"Endometrial thickness and pregnancy rates after IVF: a systematic review and meta-analysis","volume":"20","author":"Kasius","year":"2014","journal-title":"Hum Reprod Update"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/dev249","article-title":"Risk of ectopic pregnancy is linked to endometrial thickness in a retrospective cohort study of 8120 assisted reproduction technology cycles","volume":"30","author":"Rombauts","year":"2015","journal-title":"Hum Reprod"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.3389\/fendo.2023.1066922","article-title":"Endometrial thickness and early pregnancy complications after frozen-thawed embryo transfers","volume":"14","author":"Song","year":"2023","journal-title":"Front Endocrinol (Lausanne)"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1016\/s0015-0282(98)00413-0","article-title":"The detrimental effect of increased endometrial thickness on implantation and pregnancy rates and outcome in an in vitro fertilization program","volume":"71","author":"Weissman","year":"1999","journal-title":"Fertil Steril"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/deu240","article-title":"Risk of placenta praevia is linked to endometrial thickness in a retrospective cohort study of 4537 singleton assisted reproduction technology births","volume":"29","author":"Rombauts","year":"2014","journal-title":"Hum Reprod"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1080\/09513590.2023.2217269","article-title":"A thinner endometrium is associated with lower newborn birth weight during in vitro fertilization-frozen-embryo transfer: a cohort study","volume":"39","author":"Zhang","year":"2023","journal-title":"Gynecol Endocrinol"},{"key":"B13","doi-asserted-by":"publisher","first-page":"36","DOI":"10.1016\/j.fertnstert.2023.10.028","article-title":"Thick endometrium is associated with hypertensive disorders of pregnancy in programmed frozen-thawed embryo transfers: a retrospective analysis of 2,275 singleton deliveries","volume":"121","author":"Meng","year":"2024","journal-title":"Fertil Steril"},{"key":"B14","doi-asserted-by":"publisher","first-page":"hoad28","DOI":"10.1093\/hropen\/hoad028","article-title":"The thicker the endometrium, the better the neonatal outcomes","volume":"2023","author":"Wu","year":"2023","journal-title":"Hum Reprod Open"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.1016\/j.rbmo.2021.04.014","article-title":"Endometrial thickness in the prediction of neonatal adverse outcomes in frozen cycles for singleton pregnancies","volume":"43","author":"Hu","year":"2021","journal-title":"Reprod BioMed Online"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1016\/j.rbmo.2021.08.021","article-title":"Association between endometrial thickness and birth weight in fresh IVF\/ICSI embryo transfers: a retrospective cohort study of 9273 singleton births","volume":"43","author":"Liu","year":"2021","journal-title":"Reprod BioMed Online"},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2006.04.038","article-title":"Factors influencing adverse perinatal outcomes in pregnancies achieved through use of in vitro fertilization","volume":"86","author":"Chung","year":"2006","journal-title":"Fertil Steril"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.1016\/j.rbmo.2018.05.013","article-title":"Endometrial thickness of less than 7.5 mm is associated with obstetric complications in fresh IVF cycles: a retrospective cohort study","volume":"37","author":"Oron","year":"2018","journal-title":"Reprod BioMed Online"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2019.12.014","article-title":"Endometrial thickness is associated with incidence of small-for-gestational-age infants in fresh in vitro fertilization-intracytoplasmic sperm injection and embryo transfer cycles","volume":"113","author":"Guo","year":"2020","journal-title":"Fertil Steril"},{"key":"B20","doi-asserted-by":"publisher","first-page":"48","DOI":"10.1186\/s12958-020-00597-w","article-title":"Association between endometrial thickness and neonatal outcomes in intrauterine insemination cycles: a retrospective analysis of 1,016 live-born singletons","volume":"18","author":"Huang","year":"2020","journal-title":"Reprod Biol Endocrinol"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1001\/jamapediatrics.2022.1622","article-title":"Global, regional, and national incidence and mortality of neonatal preterm birth, 1990-2019","volume":"176","author":"Cao","year":"2022","journal-title":"JAMA Pediatr"},{"key":"B22","doi-asserted-by":"publisher","DOI":"10.1002\/uog.14884","article-title":"Ovarian response is a better predictor of clinical pregnancy rate following embryo transfer than is thin endometrium or presence of an endometrioma","volume":"46","author":"Coelho","year":"2015","journal-title":"Ultrasound Obstet Gynecol"},{"key":"B23","doi-asserted-by":"publisher","DOI":"10.1007\/s00404-019-05353-z","article-title":"Endometrial thickness as a predictor of ectopic pregnancy in 1125 in vitro fertilization-embryo transfer cycles: a matched case-control study","volume":"300","author":"Liu","year":"2019","journal-title":"Arch Gynecol Obstet"},{"key":"B24","doi-asserted-by":"publisher","first-page":"393","DOI":"10.1186\/s12884-024-06589-7","article-title":"Safety profiles of offspring born from early-follicular long-acting GnRH agonist protocol and daily mid-luteal GnRH agonist protocol: a retrospective study","volume":"24","author":"Du","year":"2024","journal-title":"BMC Pregnancy Childbirth"},{"key":"B25","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/deae123","article-title":"Morphological quality on Day 3 affects the pregnancy outcomes of low-quality euploid blastocysts: a retrospective cohort study","volume":"39","author":"Zhang","year":"2024","journal-title":"Hum Reprod"},{"key":"B26","doi-asserted-by":"publisher","DOI":"10.1016\/s0015-0282(00)00518-5","article-title":"Blastocyst score affects implantation and pregnancy outcome: towards a single blastocyst transfer","volume":"73","author":"Gardner","year":"2000","journal-title":"Fertil Steril"},{"key":"B27","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0104779","article-title":"Birth weight reference percentiles for Chinese","volume":"9","author":"Dai","year":"2014","journal-title":"PloS One"},{"key":"B28","doi-asserted-by":"publisher","DOI":"10.1016\/j.rbmo.2019.09.005","article-title":"Endometrial thickness and IVF cycle outcomes: a meta-analysis","volume":"40","author":"Gao","year":"2020","journal-title":"Reprod BioMed Online"},{"key":"B29","doi-asserted-by":"publisher","first-page":"55","DOI":"10.1186\/s12958-023-01105-6","article-title":"Effect of endometrial thickness on obstetric and neonatal outcomes in assisted reproduction: a systematic review and meta-analysis","volume":"21","author":"Fang","year":"2023","journal-title":"Reprod Biol Endocrinol"},{"key":"B30","doi-asserted-by":"publisher","DOI":"10.3389\/fendo.2021.766601","article-title":"Decreased endometrial thickness is associated with higher risk of neonatal complications in women with polycystic ovary syndrome","volume":"12","author":"Huang","year":"2021","journal-title":"Front Endocrinol (Lausanne)"},{"key":"B31","doi-asserted-by":"publisher","first-page":"CD2118","DOI":"10.1002\/14651858.CD002118.pub6","article-title":"Cleavage-stage versus blastocyst-stage embryo transfer in assisted reproductive technology","volume":"5","author":"Glujovsky","year":"2022","journal-title":"Cochrane Database Syst Rev"},{"key":"B32","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/deaa032","article-title":"Obstetric and perinatal risks in 4601 singletons and 884 twins conceived after fresh blastocyst transfers: a Nordic study from the CoNARTaS group","volume":"35","author":"Spangmose","year":"2020","journal-title":"Hum Reprod"},{"key":"B33","doi-asserted-by":"publisher","first-page":"7747","DOI":"10.1038\/s41467-024-52008-y","article-title":"Effect of single blastocyst-stage versus single cleavage-stage embryo transfer on cumulative live births in women with good prognosis undergoing in vitro fertilization: Multicenter Randomized Controlled Trial","volume":"15","author":"Ma","year":"2024","journal-title":"Nat Commun"},{"key":"B34","doi-asserted-by":"publisher","DOI":"10.1136\/bmj-2024-080133","article-title":"Cumulative live birth rate of a blastocyst versus cleavage stage embryo transfer policy during in vitro fertilisation in women with a good prognosis: multicentre randomised controlled trial","volume":"386","author":"Cornelisse","year":"2024","journal-title":"BMJ"},{"key":"B35","doi-asserted-by":"publisher","DOI":"10.1080\/09513590801893117","article-title":"Vascular endothelial growth factor level changes during human embryo development in culture medium","volume":"24","author":"Artini","year":"2008","journal-title":"Gynecol Endocrinol"},{"key":"B36","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajog.2015.08.042","article-title":"Why is placentation abnormal in preeclampsia","volume":"213","author":"Fisher","year":"2015","journal-title":"Am J Obstet Gynecol"},{"key":"B37","doi-asserted-by":"publisher","first-page":"193","DOI":"10.1016\/j.ajog.2010.08.009","article-title":"The \u201cGreat Obstetrical Syndromes\u201d are associated with disorders of deep placentation","volume":"204","author":"Brosens","year":"2011","journal-title":"Am J Obstet Gynecol"},{"key":"B38","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2008.12.062","article-title":"Endometrial growth and uterine blood flow: a pilot study for improving endometrial thickness in the patients with a thin endometrium","volume":"93","author":"Takasaki","year":"2010","journal-title":"Fertil Steril"},{"key":"B39","doi-asserted-by":"publisher","DOI":"10.1055\/s-0043-111899","article-title":"Insufficient Angiogenesis: cause of abnormally thin endometrium in subfertile patients","volume":"77","author":"Alfer","year":"2017","journal-title":"Geburtshilfe Frauenheilkd"},{"key":"B40","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.2115912119","article-title":"Deciphering the endometrial niche of human thin endometrium at single-cell resolution","volume":"119","author":"Lv","year":"2022","journal-title":"Proc Natl Acad Sci U S A"},{"key":"B41","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2011.07.1096","article-title":"It\u2019s time to pay attention to the endometrium","volume":"96","author":"Casper","year":"2011","journal-title":"Fertil Steril"}],"container-title":["Frontiers in Endocrinology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fendo.2025.1574123\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,5,30]],"date-time":"2025-05-30T04:13:09Z","timestamp":1748578389000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fendo.2025.1574123\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,5,30]]},"references-count":41,"alternative-id":["10.3389\/fendo.2025.1574123"],"URL":"https:\/\/doi.org\/10.3389\/fendo.2025.1574123","relation":{},"ISSN":["1664-2392"],"issn-type":[{"value":"1664-2392","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,5,30]]},"article-number":"1574123"}}