{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,12]],"date-time":"2026-10-12T15:45:53Z","timestamp":1791819953524,"version":"4.3.4"},"reference-count":43,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2018,2,21]],"date-time":"2018-02-21T00:00:00Z","timestamp":1519171200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Scientific Research from the Japanese Ministry of Health, Labour and Welfare","award":["H26-Kagaku Ippan-002"],"award-info":[{"award-number":["H26-Kagaku Ippan-002"]}]},{"name":"The Ministry of Education, Culture, Sports, Science, and Technology; and the Japan Society for the Promotion of Science","award":["Kiban-A No.16H02645"],"award-info":[{"award-number":["Kiban-A No.16H02645"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJERPH"],"abstract":"<jats:p>From 1985 to 2013, the mean birth weight of infants in Japan decreased from 3120 g to 3000 g, and the low-birth-weight rate among live births increased from 6.3% to 9.6%. No prospective study has elucidated the risk factors for poor fetal growth and preterm birth in recent Japanese parents, such as increased parental age, maternal body figure, assisted reproductive technology (ART), and socioeconomic status. Participants were mother\u2013infant pairs (n = 18,059) enrolled in a prospective birth cohort in Hokkaido, Japan from 2002 to 2013. Parental characteristics were obtained via self-reported questionnaires during pregnancy. Medical records helped identify very-low-birth-weight (VLBW; &lt;1500g), term-small-for-gestational-age (term-SGA), and preterm-birth (PTB; &lt;37 weeks) infants. We calculated relative risks (RRs) for PTB, VLBW, and term-SGA birth based on parental characteristics. The prevalence of PTB, VLBW, and term-SGA was 4.5%, 0.4%, and 6.5%, respectively. Aged parents and ART were risk factors for PTB and VLBW. Maternal alcohol drinking during pregnancy increased the risk; a parental educational level of \u226516 years reduced risk of term-SGA. Maternal pre-pregnancy BMI of &lt;18.5 kg\/m2 increased the risk of PTB and term-SGA. The RR for low BMI was highest among mothers who have low educational level. Among various factors, appropriate nutritional education to maintain normal BMI is important to prevent PTB and term-SGA in Japan.<\/jats:p>","DOI":"10.3390\/ijerph15020369","type":"journal-article","created":{"date-parts":[[2018,2,21]],"date-time":"2018-02-21T06:33:39Z","timestamp":1519194819000},"page":"369","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":52,"title":["Different Risk Factors for Very Low Birth Weight, Term-Small-for-Gestational-Age, or Preterm Birth in Japan"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2116-4023","authenticated-orcid":false,"given":"Naomi","family":"Tamura","sequence":"first","affiliation":[{"name":"Center for Environmental and Health Sciences, Hokkaido University, Kita 12, Nishi 7, Kita-ku, Sapporo 060-0812, Japan"},{"name":"Graduate School of Health Sciences, Hokkaido University, Kita 8, Nishi 5, Kita-ku, Sapporo, Hokkaido, 060-0812, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5203-0111","authenticated-orcid":false,"given":"Tomoyuki","family":"Hanaoka","sequence":"additional","affiliation":[{"name":"Center for Environmental and Health Sciences, Hokkaido University, Kita 12, Nishi 7, Kita-ku, Sapporo 060-0812, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7541-3051","authenticated-orcid":false,"given":"Kumiko","family":"Ito","sequence":"additional","affiliation":[{"name":"Center for Environmental and Health Sciences, Hokkaido University, Kita 12, Nishi 7, Kita-ku, Sapporo 060-0812, Japan"},{"name":"Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-ku, Sapporo, 060-8638, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3065-262X","authenticated-orcid":false,"given":"Atsuko","family":"Araki","sequence":"additional","affiliation":[{"name":"Center for Environmental and Health Sciences, Hokkaido University, Kita 12, Nishi 7, Kita-ku, Sapporo 060-0812, Japan"},{"name":"Graduate School of Health Sciences, Hokkaido University, Kita 8, Nishi 5, Kita-ku, Sapporo, Hokkaido, 060-0812, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chihiro","family":"Miyashita","sequence":"additional","affiliation":[{"name":"Center for Environmental and Health Sciences, Hokkaido University, Kita 12, Nishi 7, Kita-ku, Sapporo 060-0812, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sachiko","family":"Ito","sequence":"additional","affiliation":[{"name":"Center for Environmental and Health Sciences, Hokkaido University, Kita 12, Nishi 7, Kita-ku, Sapporo 060-0812, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hisanori","family":"Minakami","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-ku, Sapporo, 060-8638, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kazutoshi","family":"Cho","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-ku, Sapporo, 060-8638, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Toshiaki","family":"Endo","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, School of Medicine, Sapporo Medical University, Chuo-ku, Sapporo, 060-8556, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kazuo","family":"Sengoku","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, Asahikawa Medical University, 2-1-1-1, Midorigaoka Higashi,. Asahikawa, 078-8510, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katsuhiko","family":"Ogasawara","sequence":"additional","affiliation":[{"name":"Center for Environmental and Health Sciences, Hokkaido University, Kita 12, Nishi 7, Kita-ku, Sapporo 060-0812, Japan"},{"name":"Faculties of Health Science, Hokkaido University, Kita12, Nishi5, Kita-ku, Sapporo, 060-0812, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Reiko","family":"Kishi","sequence":"additional","affiliation":[{"name":"Center for Environmental and Health Sciences, Hokkaido University, Kita 12, Nishi 7, Kita-ku, Sapporo 060-0812, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2018,2,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1471","DOI":"10.1186\/1471-2393-13-157","article-title":"Active and passive maternal smoking during pregnancy and birth outcomes: The Kyushu Okinawa maternal and child health study","volume":"13","author":"Miyake","year":"2013","journal-title":"BMC Pregnancy Childbirth"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1111\/j.1365-3016.2007.00916.x","article-title":"Active and passive maternal smoking during pregnancy and the risks of low birthweight and preterm birth: The generation r study","volume":"22","author":"Jaddoe","year":"2008","journal-title":"Paediatr. 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