title: Japanese secular trends in birthweight and the prevalence of low birthweight infants during the last three decades: A population-based study.
abstract: Since low birthweight has been correlated with both neonatal and long-term health, we performed this epidemiological study to evaluate the Japanese secular trends in mean birthweight and the prevalence of preterm/term low birthweight infants during the last three decades. We used population-based birth certificate data from January 1979 to December 2010. Time trends were analysed using a linear regression model. During the study period, we observed a significant decrease in the mean birthweight for singleton live births (3,152 ± 436 g in 1979 and 3,018 ± 421 g in 2010 p < 0.001) and an increase in the prevalence of preterm/term low birthweight infants. A 96.3% increase in the proportion of term low birthweight infants was observed during the study period (2.7% in 1979 and 5.3% in 2010). In addition, an increased proportion of preterm/low birthweight infants born to younger women was observed (<35 years vs. ≥35 years). These trends may be related to changing patterns in Japanese women's nutritional status and the relatively strict recommended limit on weight gain during pregnancy. Understanding the long-term trends for singleton births may allow us to identify the associated risk factors and reduce the future socioeconomic burden that is associated with low birthweight infants.
authors: Department of Obstetrics and Gynaecology, Juntendo University, Tokyo, Japan.
authors: Yo
authors: Y
authors: Takemoto
authors: St. Luke's international university, Graduate school of nursing science, Global Health Nursing, 10-1 Akashicho Chuo-ku Tokyo 104-0044, Japan.
authors: Erika
authors: E
authors: Ota
authors: Department of Statistical Science, School of Multidisciplinary Sciences, SOKENDAI (The Graduate University for Advanced Studies), Tokyo, Japan.
authors: Daisuke
authors: D
authors: Yoneoka
authors: Department of Health Policy, National Center for Child Health and Development, Tokyo, Japan.
authors: Rintaro
authors: R
authors: Mori
authors: Department of Obstetrics and Gynaecology, Juntendo University, Tokyo, Japan.
authors: Satoru
authors: S
authors: Takeda
mesh_terms: D000328:Adult; D001724:Birth Weight; D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D007234:Infant, Premature; D007564:Japan / Q000453:epidemiology; D008297:Male; D008423:Maternal Age; D016017:Odds Ratio; D011247:Pregnancy; D011256:Pregnancy Outcome; D047928:Premature Birth / Q000453:epidemiology; D015995:Prevalence; D012044:Regression Analysis; D012307:Risk Factors; D012923:Social Class; D013997:Time Factors; D055815:Young Adult