title: Occupational exposures and sick leave during pregnancy: results from a Danish cohort study.
abstract: OBJECTIVE
  This study aimed to investigate associations between work postures, lifting at work, shift work, work hours, and job strain and the risk of sick leave during pregnancy from 10-29 completed pregnancy weeks in a large cohort of Danish pregnant women.
  
  
  METHODS
  Data from 51 874 pregnancies in the Danish National Birth Cohort collected between 1996-2002 were linked to the Danish Register for Evaluation of Marginalization. Exposure information was based on telephone interviews. Hazard ratios (HR) with 95% confidence intervals (95% CI) were calculated by Cox regression analysis, using time of first episode of sick leave as the primary outcome.
  
  
  RESULTS
  We found statistically significant associations between all the predictors and risk of sick leave; for non-sitting work postures (HRrange 1.55-2.79), cumulative lifting HRtrend 1.29, 95% CI 1.26-1.31, shift work (HRevening 1.90, 95% CI 1.73-2.09, HRnight 1.52, 95% CI 1.15-2.01), monthly night shifts HRtrend 1.12, 95% CI 1.11-1.14, increasing weekly work hours HRtrend 0.93, 95% CI 0.91-0.95 and high job strain HR 1.52, 95% CI 1.42-1.63. Some exposures influenced HR in either a positive or negative time-dependent way.
  
  
  CONCLUSIONS
  Our results support previous findings and suggest that initiatives to prevent sick leave during pregnancy could be based on work conditions. Preventive measures may have important implications for pregnant women and workplaces.
authors.affiliation: Department of Occupational Medicine, Noerrebrogade 44, building 2C, Aarhus University Hospital, Aarhus, Denmark. methasen@rm.dk.
authors.forename: Mette Lausten
authors.initials: ML
authors.lastname: Hansen
authors.forename: Ane Marie
authors.initials: AM
authors.lastname: Thulstrup
authors.forename: Mette
authors.initials: M
authors.lastname: Juhl
authors.forename: Jette Kolding
authors.initials: JK
authors.lastname: Kristensen
authors.forename: Cecilia Høst
authors.initials: CH
authors.lastname: Ramlau-Hansen
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008019:Life Style; D017770:Lifting / Q000009:adverse effects; D016273:Occupational Exposure / Q000706:statistics & numerical data*; D009790:Occupations / Q000145:classification* / Q000706:statistics & numerical data; D011187:Posture / Q000502:physiology; D011247:Pregnancy; D016016:Proportional Hazards Models; D012042:Registries; D012307:Risk Factors; D018582:Sick Leave / Q000706:statistics & numerical data*; D013315:Stress, Psychological / Q000150:complications / Q000453:epidemiology / Q000209:etiology; D014940:Work Schedule Tolerance / Q000502:physiology / Q000523:psychology; D016526:Workload / Q000706:statistics & numerical data; D017132:Workplace; D055815:Young Adult