title: Fixed or Rotating Night Shift Work Undertaken by Women: Implications for Fertility and Miscarriage.
abstract: This review summarizes the evidence concerning effects of night shift work on women's reproductive health, specifically difficulty in conceiving and miscarriage. We distinguish between fixed night shift and rotating night shift, as the population subgroups exposed, the social and biological mechanisms, and the magnitude of effects are likely to differ; of note, women working fixed night shift are known to have high tolerance for this schedule. We identified two relevant systematic reviews with meta-analyses and five additional studies. Night shift work may give rise to menstrual cycle disturbances, but effect sizes are imprecise. Endometriosis may be elevated in night shift workers, but evidence is only preliminary. Adequate data are lacking to assess associations between night shift work and infertility or time to pregnancy. The weight of evidence begins to point to working at night, whether in fixed or rotating shifts, as a risk factor for miscarriage. There are many methodological problems with this literature, with substantial variation in the definitions of night shift and schedule types making comparisons between studies difficult and pooling across studies questionable. Nevertheless, there appears to be grounds for caution and counselling where women have concerns about night shift work and their reproductive health.
authors: Discipline of Obstetrics and Gynaecology, University of Adelaide, Adelaide, South Australia, Australia.
authors: Renae C
authors: RC
authors: Fernandez
authors: Department of Obstetrics and Gynaecology, University of Melbourne, Parkville, Victoria, Australia.
authors: Jennifer L
authors: JL
authors: Marino
authors: Discipline of Obstetrics and Gynaecology, University of Adelaide, Adelaide, South Australia, Australia.
authors: Tamara J
authors: TJ
authors: Varcoe
authors: Department of Epidemiology, School of Public Health, University of Washington, Seattle, Washington.
authors: Scott
authors: S
authors: Davis
authors: Discipline of Obstetrics and Gynaecology, University of Adelaide, Adelaide, South Australia, Australia.
authors: Lisa J
authors: LJ
authors: Moran
authors: Discipline of Obstetrics and Gynaecology, University of Adelaide, Adelaide, South Australia, Australia.
authors: Alice R
authors: AR
authors: Rumbold
authors: Discipline of Obstetrics and Gynaecology, University of Adelaide, Adelaide, South Australia, Australia.
authors: Hannah M
authors: HM
authors: Brown
authors: Discipline of Public Health, University of Adelaide, Adelaide, South Australia, Australia.
authors: Melissa J
authors: MJ
authors: Whitrow
authors: Discipline of Obstetrics and Gynaecology, University of Adelaide, Adelaide, South Australia, Australia.
authors: Michael J
authors: MJ
authors: Davies
authors: Discipline of Public Health, University of Adelaide, Adelaide, South Australia, Australia.
authors: Vivienne M
authors: VM
authors: Moore
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology*; D005260:Female; D005298:Fertility; D006801:Humans; D007247:Infertility, Female / Q000453:epidemiology* / Q000503:physiopathology; D008019:Life Style; D010561:Personnel Staffing and Scheduling; D011247:Pregnancy; D012098:Reproduction; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014940:Work Schedule Tolerance; D016526:Workload