Rotating shift work may affect fertility: study

April 6, 2011

New York – Women who work rotating shifts may be more likely to experience shifting menstrual cycles, indicates a new study on the link between work schedules and fertility.

According to a study abstract, researchers performed a cross-sectional analysis on rotating shift work and menstrual cycle patterns of 71,077 nurses between 28 and 45 years old who were not having menstrual periods and were not using oral contraceptives in 1993.

Findings show shift workers who experience sleep disturbances and exposure to light at night could be at increased risk for changes in physiologic functions that are circadian in nature. Additional findings show:

  • 70 percent reported menstrual cycles of 26 to 31 days
  • Women with 20 or more months of rotating shift work were more likely to have irregular menstrual cycles
  • Women who experienced irregular cycle patterns of 40 or more days had evidence of changes as rotating shift work increased

Researchers concluded that shift work was “modestly associated with menstrual function” and could have possible implications for fertility and other cycle-related aspects of women’s health. The study was published in the journal Epidemiology.