title: Association of maternal age with child health: A Japanese longitudinal study.
abstract: Average maternal age at birth has been rising steadily in Western and some Asian countries. Older maternal age has been associated with adverse pregnancy and birth outcomes; however, studies on the relationship between maternal age and young children's health remain scarce. Therefore, we sought to investigate the association of maternal age with child health outcomes in the Japanese population. We analyzed data from two birth cohorts of the nationwide Japanese Longitudinal Survey of Babies in 21st Century (n2001 = 47,715 and n2010 = 38,554). We estimated risks of unintentional injuries and hospital admissions at 18 and 66 months according to maternal age, controlling for the following potential confounders: parental education; maternal parity, smoking status, and employment status; household income; paternal age, and sex of the child. We also included the following as potential mediators: preterm births and birthweight. We observed a decreasing trend in the risks of children's unintentional injuries and hospital admissions at 18 months according to maternal age in both cohorts. In the 2001 cohort, compared to mothers <25 years, odds ratios of hospital admission at 18 months were 0.97 [95% CI: 0.86, 1.09], 0.92 [0.81, 1.05], 0.76 [0.65, 0.90], and 0.71 [0.51, 0.98] for mothers aged 25.0-29.9, 30.0-34.9, 35.0-39.9, and >40.0 years, respectively, controlling for confounders. Our findings were in line with previous findings from population-based studies conducted in the United Kingdom and Canada suggesting that older maternal age may be beneficial for early child health.
authors.affiliation: Department of Social Medicine, National Center for Child Health and Development, Tokyo, Japan.
authors.forename: Tsuguhiko
authors.identifier: http://orcid.org/0000-0002-6009-7962
authors.initials: T
authors.lastname: Kato
authors.affiliation: Department of Human Ecology, Okayama University Graduate School of Environmental and Life Science, Okayama, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yorifuji
authors.affiliation: Center for Regional Research, Okayama University, Okayama, Japan.
authors.forename: Michiyo
authors.initials: M
authors.lastname: Yamakawa
authors.affiliation: Department of Nursing, Okayama Prefectural University Graduate School of Health and Welfare Science, Okayama, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Inoue
authors.affiliation: Department of Epidemiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Doi
authors.affiliation: Department of Public Health and Health Policy, Institute of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Eboshida
authors.affiliation: Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, MA, United States of America.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kawachi
mesh_terms: D000061:Accidents, Home / Q000706:statistics & numerical data; D000328:Adult; D001724:Birth Weight / Q000502:physiology*; D002648:Child; D000067576:Child Health / Q000639:trends*; D002675:Child, Preschool; D004522:Educational Status; D004651:Employment / Q000523:psychology / Q000706:statistics & numerical data; D005260:Female; D005865:Gestational Age; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000254:growth & development*; D007564:Japan / Q000453:epidemiology; D008137:Longitudinal Studies; D008423:Maternal Age; D016017:Odds Ratio; D010298:Parity / Q000502:physiology; D010331:Paternal Age; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology; D012307:Risk Factors; D012907:Smoking / Q000503:physiopathology