{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,25]],"date-time":"2026-09-25T20:51:23Z","timestamp":1790369483540,"version":"4.1.0"},"reference-count":49,"publisher":"BMJ","issue":"4","license":[{"start":{"date-parts":[[2020,4,28]],"date-time":"2020-04-28T00:00:00Z","timestamp":1588032000000},"content-version":"unspecified","delay-in-days":27,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001700","name":"Ministry of Education, Culture, Sports, Science and Technology","doi-asserted-by":"publisher","award":["KAKENHI 15K08731 and 18K10076"],"award-info":[{"award-number":["KAKENHI 15K08731 and 18K10076"]}],"id":[{"id":"10.13039\/501100001700","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100009619","name":"Japan Agency for Medical Research and Development","doi-asserted-by":"crossref","award":["17gk0110013h00002"],"award-info":[{"award-number":["17gk0110013h00002"]}],"id":[{"id":"10.13039\/100009619","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2020,4,3]]},"published-print":{"date-parts":[[2020,4]]},"abstract":"<jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>This study aimed to identify intrauterine growth differences according to infertility treatment compared with spontaneous conception and to describe intrauterine growth trajectories.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design<\/jats:title>\n                    <jats:p>Retrospective cohort study.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Setting<\/jats:title>\n                    <jats:p>A single primary and tertiary medical centre in Japan.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Participants<\/jats:title>\n                    <jats:p>This study included singleton pregnant women with prenatal check-ups and delivery at the University of Yamanashi Hospital between 1 July 2012 and 30 September 2017. Patients were divided into four groups: spontaneous conception, infertility treatment without assisted reproductive technology (ART), fresh-embryo transfer and frozen embryo transfer (FET).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Interventions<\/jats:title>\n                    <jats:p>Differences in intrauterine growth according to the infertility treatment, including ART, and birth weight were evaluated. Multilevel analysis was employed to evaluate intrauterine growth trajectories stratified by the sex of the offspring.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Primary outcome measure<\/jats:title>\n                    <jats:p>Estimated fetal weight (EFW) assessed by ultrasound examination.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>We assessed data from 37\u2009239 prenatal examination results from 2377 pregnant women (spontaneous conception, n=1764; infertility treatment without ART, n=171; fresh-embryo transfer, n=112; and FET, n=330) in the final analysis. Multilevel analysis was adjusted for gestation duration, gestation period, parity, hypertensive disorders of pregnancy, type of infertility treatment, maternal age, smoking status, placenta previa, thyroid disease, gestational diabetes mellitus and the interaction between each potential confounding factor and gestation duration. In male fetuses, the interaction between FET and gestational duration (estimate: 0.36; 95% CI: 0.06 to 0.67) significantly affected the EFW. Similarly, in female fetuses, FET (estimate: \u221269.85; 95%\u2009CI: \u2212112.09 to \u221227.61) and the interaction between FET and gestation duration (estimate: 0.57; 95%\u2009CI: 0.28 to 0.87) significantly affected the EFW.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>This study shows that FET affects intrauterine growth trajectory from the second trimester to term, particularly in female fetuses. Our findings require further prospective research to examine the effect of infertility treatment on fetal growth.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2019-033675","type":"journal-article","created":{"date-parts":[[2020,4,29]],"date-time":"2020-04-29T03:56:35Z","timestamp":1588132595000},"page":"e033675","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":7,"title":["Association between infertility treatment and intrauterine growth: a multilevel analysis in a retrospective cohort study"],"prefix":"10.1136","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3124-1141","authenticated-orcid":false,"given":"Satoshi","family":"Shinohara","sequence":"first","affiliation":[{"name":"Department of Obstetrics and Gynecology, Yamanashi Daigaku Igakubu, Chuo, Yamanashi, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shuji","family":"Hirata","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, Yamanashi Daigaku Igakubu, Chuo, Yamanashi, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8151-6927","authenticated-orcid":false,"given":"Kohta","family":"Suzuki","sequence":"additional","affiliation":[{"name":"Department of Health and Psychosocial Medicine, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2020,4,28]]},"reference":[{"key":"2025121220010686000_10.4.e033675.1","doi-asserted-by":"publisher","DOI":"10.1186\/1477-7827-8-21"},{"key":"2025121220010686000_10.4.e033675.2","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/deq124"},{"key":"2025121220010686000_10.4.e033675.3","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1016\/j.fertnstert.2016.06.028","article-title":"A fresh(er) perspective on frozen embryo transfers","volume":"106","author":"Pereira","year":"2016","journal-title":"Fertil Steril"},{"key":"2025121220010686000_10.4.e033675.4","doi-asserted-by":"publisher","DOI":"10.1002\/rmb2.12074"},{"key":"2025121220010686000_10.4.e033675.5","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/dep477"},{"key":"2025121220010686000_10.4.e033675.6","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2009.05.091"},{"key":"2025121220010686000_10.4.e033675.7","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2011.05.073"},{"key":"2025121220010686000_10.4.e033675.8","doi-asserted-by":"crossref","first-page":"3879","DOI":"10.3109\/14767058.2016.1151868","article-title":"Differential effect of mode of conception and infertility treatment on fetal growth and prematurity","volume":"29","author":"Valenzuela-Alcaraz","year":"2016","journal-title":"J Matern Fetal Neonatal Med"},{"key":"2025121220010686000_10.4.e033675.9","doi-asserted-by":"crossref","first-page":"1703","DOI":"10.1016\/j.fertnstert.2016.08.047","article-title":"Obstetric and perinatal outcomes after either fresh or thawed frozen embryo transfer: an analysis of 112,432 singleton pregnancies recorded in the human fertilisation and embryology authority anonymized dataset","volume":"106","author":"Maheshwari","year":"2016","journal-title":"Fertil Steril"},{"key":"2025121220010686000_10.4.e033675.10","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2012.09.003"},{"key":"2025121220010686000_10.4.e033675.11","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1016\/j.fertnstert.2016.03.049","article-title":"Comparison of birth weights in patients randomly assigned to fresh or frozen-thawed embryo transfer","volume":"106","author":"Shapiro","year":"2016","journal-title":"Fertil Steril"},{"key":"2025121220010686000_10.4.e033675.12","first-page":"391","article-title":"Developmental origins of health and disease: environmental exposures","volume":"27","author":"Swanson","year":"2000","journal-title":"SeminReprod Med"},{"key":"2025121220010686000_10.4.e033675.13","doi-asserted-by":"crossref","first-page":"1469","DOI":"10.1111\/jog.12419","article-title":"Guidelines for obstetrical practice in Japan: Japan Society of obstetrics and gynecology (JSOG) and Japan association of obstetricians and Gynecologists (JAOG) 2014 edition","volume":"40","author":"Minakami","year":"2014","journal-title":"J Obstet Gynaecol Res"},{"key":"2025121220010686000_10.4.e033675.14","doi-asserted-by":"crossref","DOI":"10.1186\/s13052-016-0254-7","article-title":"Incidence of infants born small- and large-for-gestational-age in an Italian cohort over a 20-year period and associated risk factors","volume":"42","author":"Chiavaroli","year":"2016","journal-title":"Ital J Pediatr"},{"key":"2025121220010686000_10.4.e033675.15","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1111\/ppe.12172","article-title":"Maternal thyroid dysfunction during gestation, preterm delivery, and birthweight. The Infancia Y Medio Ambiente cohort, Spain","volume":"29","author":"Le\u00f3n","year":"2015","journal-title":"Paediatr Perinat Epidemiol"},{"key":"2025121220010686000_10.4.e033675.16","doi-asserted-by":"crossref","first-page":"1080","DOI":"10.1111\/1471-0528.12628","article-title":"Differences in risk factors for incident and recurrent small-for-gestational-age birthweight: a hospital-based cohort study","volume":"121","author":"Hinkle","year":"2014","journal-title":"BJOG"},{"key":"2025121220010686000_10.4.e033675.17","doi-asserted-by":"crossref","first-page":"295","DOI":"10.1007\/s00404-012-2296-4","article-title":"Effect of placenta previa on fetal growth restriction and stillbirth","volume":"286","author":"Yeniel","year":"2012","journal-title":"Arch Gynecol Obstet"},{"key":"2025121220010686000_10.4.e033675.18","doi-asserted-by":"crossref","first-page":"39","DOI":"10.14390\/jsshp.HRP2017-018","article-title":"New definition and classification of \u201cHypertensive Disorders of Pregnancy (HDP)\u201d","volume":"5","author":"Watanabe","year":"2017","journal-title":"Hypertens Res Pregnancy"},{"key":"2025121220010686000_10.4.e033675.19","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0118538","article-title":"Childhood growth trajectories according to combinations of pregestational weight status and maternal smoking during pregnancy: a multilevel analysis","volume":"10","author":"Suzuki","year":"2015","journal-title":"PLoS One"},{"key":"2025121220010686000_10.4.e033675.20","doi-asserted-by":"publisher","DOI":"10.1186\/1471-2393-12-23"},{"key":"2025121220010686000_10.4.e033675.21","doi-asserted-by":"crossref","first-page":"261","DOI":"10.1016\/S1701-2163(16)32401-X","article-title":"Diagnosis and management of placenta previa","volume":"29","author":"Oppenheimer","year":"2007","journal-title":"J Obstet Gynaecol Can"},{"key":"2025121220010686000_10.4.e033675.22","doi-asserted-by":"crossref","first-page":"228","DOI":"10.1016\/S2213-8587(13)70109-8","article-title":"Hypothyroidism in pregnancy","volume":"1","author":"Teng","year":"2013","journal-title":"Lancet Diabetes Endocrinol"},{"key":"2025121220010686000_10.4.e033675.23","first-page":"87","article-title":"Ellipse tracing fetal growth assessment using abdominal circumference: JSUM standardization Committee for fetal measurements","volume":"8","author":"Shinozuka","year":"2000","journal-title":"J Med Ultrasound"},{"key":"2025121220010686000_10.4.e033675.24","doi-asserted-by":"publisher","DOI":"10.1046\/j.1469-0705.2000.00024.x"},{"key":"2025121220010686000_10.4.e033675.25","doi-asserted-by":"publisher","DOI":"10.1159\/000438451"},{"key":"2025121220010686000_10.4.e033675.26","doi-asserted-by":"publisher","DOI":"10.1037\/a0012765"},{"key":"2025121220010686000_10.4.e033675.27","doi-asserted-by":"publisher","DOI":"10.1111\/ppe.12116"},{"key":"2025121220010686000_10.4.e033675.28","doi-asserted-by":"crossref","first-page":"275","DOI":"10.2188\/jea.JE20120164","article-title":"Multilevel longitudinal analysis of sex differences in height gain and growth rate changes in Japanese school-aged children","volume":"23","author":"Zheng","year":"2013","journal-title":"J Epidemiol"},{"key":"2025121220010686000_10.4.e033675.29","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1038\/ijo.2010.198","article-title":"Gender differences in the association between maternal smoking during pregnancy and childhood growth trajectories: multilevel analysis","volume":"35","author":"Suzuki","year":"2011","journal-title":"Int J Obes"},{"key":"2025121220010686000_10.4.e033675.30","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1007\/s10815-015-0601-4","article-title":"Independent factors influencing large-for-gestation birth weight in singletons born after in vitro fertilization","volume":"33","author":"Korosec","year":"2016","journal-title":"J Assist Reprod Genet"},{"key":"2025121220010686000_10.4.e033675.31","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2013.10.011"},{"key":"2025121220010686000_10.4.e033675.32","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1016\/j.rbmo.2016.04.014","article-title":"Higher \u03b2-hCG concentrations and higher birthweights ensue from single vitrified embryo transfers","volume":"33","author":"Keane","year":"2016","journal-title":"Reprod Biomed Online"},{"key":"2025121220010686000_10.4.e033675.33","doi-asserted-by":"publisher","DOI":"10.1164\/rccm.200303-374OC"},{"key":"2025121220010686000_10.4.e033675.34","doi-asserted-by":"publisher","DOI":"10.1016\/j.jsgi.2006.06.006"},{"key":"2025121220010686000_10.4.e033675.35","doi-asserted-by":"crossref","DOI":"10.1186\/s13293-016-0119-1","article-title":"Sex-Specific differences in fetal and infant growth patterns: a prospective population-based cohort study","volume":"7","author":"Broere-Brown","year":"2016","journal-title":"Biol Sex Differ"},{"key":"2025121220010686000_10.4.e033675.36","doi-asserted-by":"publisher","DOI":"10.1093\/ije\/dyu036"},{"key":"2025121220010686000_10.4.e033675.37","doi-asserted-by":"crossref","first-page":"1137","DOI":"10.1111\/j.1447-0756.2012.01848.x","article-title":"Gestational bodyweight gain among underweight Japanese women related to small-for-gestational-age birth","volume":"38","author":"Harita","year":"2012","journal-title":"J Obstet Gynaecol Res"},{"key":"2025121220010686000_10.4.e033675.38","doi-asserted-by":"crossref","DOI":"10.1186\/1475-9276-12-28","article-title":"Contribution of socioeconomic status to the risk of small for gestational age infants--a population-based study of 1,390,165 singleton live births in Finland","volume":"12","author":"R\u00e4is\u00e4nen","year":"2013","journal-title":"Int J Equity Health"},{"key":"2025121220010686000_10.4.e033675.39","doi-asserted-by":"publisher","DOI":"10.1159\/000357592"},{"key":"2025121220010686000_10.4.e033675.40","doi-asserted-by":"crossref","first-page":"1471","DOI":"10.1111\/1471-0528.13910","article-title":"Donor oocyte conception and pregnancy complications: a systematic review and meta-analysis","volume":"123","author":"Jeve","year":"2016","journal-title":"BJOG"},{"key":"2025121220010686000_10.4.e033675.41","doi-asserted-by":"crossref","first-page":"1065","DOI":"10.4239\/wjd.v6.i8.1065","article-title":"Gestational diabetes: a clinical update","volume":"6","author":"Kampmann","year":"2015","journal-title":"World J Diabetes"},{"key":"2025121220010686000_10.4.e033675.42","doi-asserted-by":"crossref","first-page":"371","DOI":"10.2188\/jea.JE20150185","article-title":"Association between maternal smoking during pregnancy and birth weight: an appropriately adjusted model from the Japan environment and children's study","volume":"26","author":"Suzuki","year":"2016","journal-title":"J Epidemiol"},{"key":"2025121220010686000_10.4.e033675.43","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1038\/hr.2016.126","article-title":"Epidemiology of hypertensive disorders in pregnancy: prevalence, risk factors, predictors and prognosis","volume":"40","author":"Umesawa","year":"2017","journal-title":"Hypertens Res"},{"key":"2025121220010686000_10.4.e033675.44","doi-asserted-by":"publisher","DOI":"10.1089\/105072502761016485"},{"key":"2025121220010686000_10.4.e033675.45","doi-asserted-by":"crossref","first-page":"538","DOI":"10.1111\/j.1447-0756.2010.01408.x","article-title":"Comparison of risk factors for placental abruption and placenta previa: case-cohort study","volume":"37","author":"Matsuda","year":"2011","journal-title":"J Obstet Gynaecol Res"},{"key":"2025121220010686000_10.4.e033675.46","doi-asserted-by":"publisher","DOI":"10.1515\/JPM.2004.028"},{"key":"2025121220010686000_10.4.e033675.47","doi-asserted-by":"crossref","first-page":"617","DOI":"10.7863\/jum.2009.28.5.617","article-title":"Sonographic fetal weight estimation: which model should be used?","volume":"28","author":"Melamed","year":"2009","journal-title":"J Ultrasound Med"},{"key":"2025121220010686000_10.4.e033675.48","doi-asserted-by":"publisher","DOI":"10.7863\/ultra.32.5.815"},{"key":"2025121220010686000_10.4.e033675.49","doi-asserted-by":"crossref","first-page":"487","DOI":"10.1007\/s00404-015-3989-2","article-title":"Accuracy of sonographic fetal weight estimation: influence of the scan-to-delivery interval in combination with the applied weight estimation formula","volume":"294","author":"Faschingbauer","year":"2016","journal-title":"Arch Gynecol Obstet"}],"container-title":["BMJ Open"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bmjopen-2019-033675","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,13]],"date-time":"2025-12-13T04:01:18Z","timestamp":1765598478000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmjopen.bmj.com\/lookup\/doi\/10.1136\/bmjopen-2019-033675"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,4]]},"references-count":49,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2020,4,28]]},"published-print":{"date-parts":[[2020,4]]}},"alternative-id":["10.1136\/bmjopen-2019-033675"],"URL":"https:\/\/doi.org\/10.1136\/bmjopen-2019-033675","relation":{},"ISSN":["2044-6055","2044-6055"],"issn-type":[{"value":"2044-6055","type":"print"},{"value":"2044-6055","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,4]]}}}