title: Effect of rotating shift work on childbearing and birth weight: a study of women working in a semiconductor manufacturing factory.
abstract: BACKGROUND
  Stable circadian rhythm is important for both maternal and fetal health. This retrospective analysis of women in a semiconductor factory evaluated the effect of shift work exposure on childbearing and birth weight.
  
  
  METHODS
  Records of 440 female employees (initial mean age: 28.4 years) including 111 mothers who had 158 live births during the period of observation (1997-2007) were reviewed. The data analyzed included maternal age, general health condition, highest educational level, life-style and occupational factors, as well as newborn gender, birth weight, birth order and gestational age.
  
  
  RESULTS
  The childbearing rates of female workers on three different work schedules (consistent daytime work (CDW), intermittent (i-) or persistent (p-) rotating shift works (RSW)) were 32.1%, 20.0% and 25.4%, respectively (P=0.047). After controlling for potential confounding factors, childbearing rates among women with CDW exceeded those of shift workers (odds ratio (OR), 1.7; 95% confidence interval (CI), 1.0-3.0). The birth weights of newborns from mothers on the three work schedules (CDW, i-RSW and p-RSW) were significantly different (3271.7±395.4, 3251.3±460.9, and 2998.5±381.2 g, respectively (P<0.01). Newborns within the lightest birth weight quintile were significantly more likely to be born to mothers with exposure to p-RSW (OR, 4.3; 95% CI, 1.1-16.8).
  
  
  CONCLUSIONS
  Rotating shift work exposure was significantly associated with decreased childbearing and lighter birth weight in women working in this semiconductor manufacturing factory. Work schedules should be carefully planned for female employees who are pregnant or preparing for pregnancy. Prenatal evaluations for mothers with persistent day-night rotating shift work exposures are especially necessary.
authors.affiliation: The Department of Occupational Medicine, En Chu Kong Hospital, New Taipei City, 23742 Taiwan, China.
authors.forename: Yu-Cheng
authors.initials: YC
authors.lastname: Lin
authors.forename: Mei-Huei
authors.initials: MH
authors.lastname: Chen
authors.forename: Chia-Jung
authors.initials: CJ
authors.lastname: Hsieh
authors.forename: Pau-Chung
authors.initials: PC
authors.lastname: Chen
mesh_terms: D000328:Adult; D001724:Birth Weight / Q000502:physiology*; D021081:Chronobiology Disorders; D002940:Circadian Rhythm; D004651:Employment; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008019:Life Style; D016015:Logistic Models; D008423:Maternal Age; D008429:Maternal Welfare; D016272:Occupational Health; D010561:Personnel Staffing and Scheduling; D012189:Retrospective Studies; D012666:Semiconductors; D012892:Sleep Deprivation / Q000503:physiopathology