{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T13:31:31Z","timestamp":1791466291591,"version":"4.3.4"},"reference-count":28,"publisher":"Public Library of Science (PLoS)","issue":"7","license":[{"start":{"date-parts":[[2022,7,25]],"date-time":"2022-07-25T00:00:00Z","timestamp":1658707200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:p>Multiple pregnancies pose a high risk of morbidity and mortality in both mothers and infants; thus, obtaining reliable information based on a large population is essential to improve management. We used the maternal and child health statistics, which are published annually, from the database of the Ministry of Health, Labor, and Welfare. The data obtained were aggregated in 5-year intervals, and we used them to analyze the proportion of the number of births for each week of pregnancy to the total of each singleton and multiple pregnancy. For perinatal health indicators (perinatal mortality, stillbirth, and neonatal mortality), the obtained data were calculated and plotted on graphs for each week of pregnancy. Moreover, these indicators were calculated by dividing them into first twin and second twin fetuses. Stillbirth weights were aggregated in several groups, and a histogram was displayed. Between 2000 and 2019, there were 21,068,275 live births, 67,666 stillbirths, and 16,443 early neonatal deaths, excluding 7,148 (7,104 singletons, 44 multiple births) cases, in which the exact gestational weeks at birth were unknown. More than 95% of multiple pregnancies were twin births. Perinatal mortality, stillbirth, and early neonatal mortality rates in multiple pregnancies were the lowest at approximately 37 weeks of gestation and lower than those of single pregnancies at approximately 36 weeks of gestation. Perinatal mortality and stillbirth rates were higher during the delivery of the second twins than the first-born twins, but the early neonatal mortality rate remained approximately the same during the delivery of both twins. As the data in the government database are accumulated and published continuously, indicators can be calculated in the future using the method presented in this study. Further, our findings may be useful for policymaking related to managing multiple pregnancies.<\/jats:p>","DOI":"10.1371\/journal.pone.0272075","type":"journal-article","created":{"date-parts":[[2022,7,25]],"date-time":"2022-07-25T17:31:42Z","timestamp":1658770302000},"page":"e0272075","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":10,"title":["Time trend analysis of perinatal mortality, stillbirth, and early neonatal mortality of multiple pregnancies for each gestational week from the year 2000 to 2019: A population-based study in Japan"],"prefix":"10.1371","volume":"17","author":[{"given":"Eijiro","family":"Hayata","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3621-1251","authenticated-orcid":true,"given":"Masahiko","family":"Nakata","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mineto","family":"Morita","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2022,7,25]]},"reference":[{"key":"pone.0272075.ref001","doi-asserted-by":"crossref","first-page":"938","DOI":"10.1016\/S0002-9378(00)70350-4","article-title":"Hypertensive disorders in twin versus singleton gestations. 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Guidance. Multiple pregnancy: the management of twin and triplet pregnancies in the antenatal period. London: Royal College of Obstetricians and Gynaecologists Press. National Collaborating Centre for Women\u2019s and Children\u2019s Health; 2011."},{"key":"pone.0272075.ref005","doi-asserted-by":"crossref","first-page":"50","DOI":"10.1097\/AOG.0b013e31823d7b06","article-title":"Optimum timing for planned delivery of uncomplicated monochorionic and dichorionic twin pregnancies","volume":"119","author":"FM Breathnach","year":"2012","journal-title":"Obstet Gynecol"},{"key":"pone.0272075.ref006","unstructured":"Japan Society of Obstetrics and Gynecology (JSOG), Japan Association of Obstetricians and Gynecologists (JAOG). Guidelines for obstetrical practice in Japan. Tokyo: Japan Society of Obstetrics and Gynecology; 2020 Edition (in Japanese)."},{"key":"pone.0272075.ref007","doi-asserted-by":"crossref","first-page":"1432","DOI":"10.1001\/jama.1996.03530420060037","article-title":"Reestimating date of delivery in multifetal pregnancies","volume":"275","author":"H Minakami","year":"1996","journal-title":"JAMA"},{"key":"pone.0272075.ref008","unstructured":"Vital statistics. [Cited Jul. 15 2021]. https:\/\/www.mhlw.go.jp\/toukei\/list\/81-1.html. Ministry of Health, Labour and Welfare."},{"key":"pone.0272075.ref009","unstructured":"Supplementary data of vital statistics. [Cited Jul. 15 2021]. https:\/\/www.e-stat.go.jp\/stat-search\/files?page=1&layout=datalist&toukei=00450011&tstat=000001028897&cycle=7&tclass1=000001053058&tclass2=000001053061&tclass3=000001053068&tclass4val=0."},{"key":"pone.0272075.ref010","doi-asserted-by":"crossref","first-page":"454","DOI":"10.1111\/aogs.13194","article-title":"The fetuses-at-risk approach: survival analysis from a fetal perspective","volume":"97","author":"KS Joseph","year":"2018","journal-title":"Acta Obstet Gynecol Scand"},{"key":"pone.0272075.ref011","unstructured":"Ethical guidelines for epidemiological research. [Cited Jul. 15 2021]. http:\/\/www.lifescience.mext.go.jp\/files\/pdf\/n796_01.pdf."},{"key":"pone.0272075.ref012","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1053\/j.semperi.2012.02.001","article-title":"Epidemiology of twinning in developed countries","volume":"36","author":"CV Ananth","year":"2012","journal-title":"Semin Perinatol"},{"key":"pone.0272075.ref013","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1016\/S1472-6483(10)62251-1","article-title":"Global epidemiology of multiple birth","volume":"15","author":"J. Collins","year":"2007","journal-title":"Reprod Biomed Online"},{"key":"pone.0272075.ref014","first-page":"1","article-title":"Three decades of twin births in the United States, 1980\u20132009","volume":"80","author":"JA Martin","year":"2012","journal-title":"NCHS Data Brief"},{"key":"pone.0272075.ref015","doi-asserted-by":"crossref","first-page":"e0209962","DOI":"10.1371\/journal.pone.0209962","article-title":"Temporal trends in the birth rates and perinatal mortality of twins: A population-based study in China","volume":"14","author":"C Deng","year":"2019","journal-title":"PLOS ONE"},{"key":"pone.0272075.ref016","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1053\/sper.2002.34775","article-title":"Trends in the occurrence, determinants, and consequences of multiple births","volume":"26","author":"B Blondel","year":"2002","journal-title":"Semin Perinatol"},{"key":"pone.0272075.ref017","first-page":"1","article-title":"Is twin childbearing on the decline? 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Japan Society for Reproductive Medicine; 2007."},{"key":"pone.0272075.ref020","doi-asserted-by":"crossref","first-page":"437","DOI":"10.1001\/jamapediatrics.2019.6317","article-title":"Association of gestational age at birth With risk of perinatal mortality and special educational need Among twins","volume":"174","author":"S Murray","year":"2020","journal-title":"JAMA Pediatr"},{"key":"pone.0272075.ref021","doi-asserted-by":"crossref","first-page":"964","DOI":"10.1111\/j.1471-0528.2012.03356.x","article-title":"Elective birth at 37 weeks of gestation versus standard care for women with an uncomplicated twin pregnancy at termml: the Twins Timing of Birth Randomised Trial","volume":"119","author":"Twins Timing of Birth Trial Group","year":"2012","journal-title":"BJOG"},{"key":"pone.0272075.ref022","doi-asserted-by":"crossref","first-page":"1117","DOI":"10.1093\/aje\/152.12.1117","article-title":"Invited commentary: intersecting perinatal mortality curves by gestational age-are appearances deceiving?","volume":"152","author":"RT Lie","year":"2000","journal-title":"Am J Epidemiol"},{"key":"pone.0272075.ref023","doi-asserted-by":"crossref","first-page":"417","DOI":"10.1111\/j.1365-3016.2009.01051.x","article-title":"Commentary: Exegesis of effect modification\u2014biological or spurious?","volume":"23","author":"KS Joseph","year":"2009","journal-title":"Paediatr Perinat Epidemiol"},{"key":"pone.0272075.ref024","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1186\/1471-2393-3-3","article-title":"A parsimonious explanation for intersecting perinatal mortality curves: understanding the effect of plurality and of parity","volume":"3","author":"KS Joseph","year":"2003","journal-title":"BMC Pregnancy Childbirth"},{"key":"pone.0272075.ref025","doi-asserted-by":"crossref","first-page":"1192","DOI":"10.1016\/S0140-6736(87)92154-4","article-title":"Risk of unexplained stillbirth at different gestational ages","volume":"1","author":"PL Yudkin","year":"1987","journal-title":"Lancet"},{"key":"pone.0272075.ref026","unstructured":"Annual report of Perinatal committee. [Cited Jul. 15 2021]. http:\/\/www.jsog.or.jp\/modules\/committee\/index.php?content_id=8. Japan Society of Obstetrics and Gynecology."},{"key":"pone.0272075.ref027","doi-asserted-by":"crossref","first-page":"153.e1","DOI":"10.1016\/j.ajog.2014.02.024","article-title":"Perinatal mortality in second- vs firstborn twins: a matter of birth size or birth order?","volume":"211","author":"ZC Luo","year":"2014","journal-title":"Am J Obstet Gynecol"},{"key":"pone.0272075.ref028","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1097\/01.AOG.0000101291.14773.F0","article-title":"Perinatal mortality in first- and second-born twins in the United States","volume":"103","author":"W Sheay","year":"2004","journal-title":"Obstet Gynecol"}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0272075","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,7,25]],"date-time":"2022-07-25T17:32:15Z","timestamp":1658770335000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0272075"}},"subtitle":[],"editor":[{"given":"Garumma Tolu","family":"Feyissa","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2022,7,25]]},"references-count":28,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2022,7,25]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0272075","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,7,25]]}}}