title: Characteristics of menstrual cycle in shift workers.
abstract: BACKGROUND
  In this study, the characteristics of menstrual cycle in shift workers employed in the pharmaceutical industry are investigated.
  
  
  METHODS
  This study was conducted in a pharmaceutical industrial complex in Tehran in 2012. 406 female workers in packaging units were studied on the menstrual cycle characteristics. The studied workers were divided into two groups of shift workers and non-shift workers and were compared in terms of the frequency of menstrual disorder (short-term cycle, long-term cycle, irregular cycle and bleeding during menstrual cycle) as well as hormonal values (FSH, LH, TSH, and Prolactin).
  
  
  RESULTS
  The odds ratio (OR) for menstrual disorder in the shift workers was 5.54 (95% CI=2.78-11.02) compared to the non-shift workers. The mean difference of hormonal values (except prolactin) between shift workers and non-shift workers was not significant (P>0.05).
  
  
  CONCLUSIONS
  This study suggests that shift work may disrupt the menstrual cycle.
authors.affiliation: Occupational Medicine Department- School of Medicine- Tehran University of Medical Sciences, Terhan, Iran. drmsattarchi@gmail.com
authors.forename: Mirsaeed
authors.initials: M
authors.lastname: Attarchi
authors.forename: Hamidreza
authors.initials: H
authors.lastname: Darkhi
authors.forename: Mahshad
authors.initials: M
authors.lastname: Khodarahmian
authors.forename: Mandana
authors.initials: M
authors.lastname: Dolati
authors.forename: Maryam
authors.initials: M
authors.lastname: Kashanian
authors.forename: Mostafa
authors.initials: M
authors.lastname: Ghaffari
authors.forename: Elham
authors.initials: E
authors.lastname: Mirzamohammadi
authors.forename: Saber
authors.initials: S
authors.lastname: Mohammadi
mesh_terms: D000328:Adult; D002940:Circadian Rhythm; D004345:Drug Industry; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007492:Iran / Q000453:epidemiology; D007986:Luteinizing Hormone / Q000097:blood; D008597:Menstrual Cycle / Q000097:blood*; D008599:Menstruation Disturbances / Q000097:blood / Q000453:epidemiology*; D016017:Odds Ratio; D011388:Prolactin / Q000097:blood; D011795:Surveys and Questionnaires; D013972:Thyrotropin / Q000097:blood; D055815:Young Adult
chemical_list: D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D013972:Thyrotropin