A new report published in the British Medical Journal (BMJ) links physically demanding jobs and shift work with lower fertility rates in women.
The researchers studied more than 470 women undergoing fertility treatment and compared the physical demands at work. The study suggests physical exertion and working odd hours changes the body's biological clock which could have a negative impact on reproduction.
"Some occupational factors have been suggested to disrupt circadian regulation which could, in turn, affect reproductive outcomes among women.
For instance, shift work, long working hours and physical factors have been found to increase the risk of menstrual cycle disturbances, spontaneous abortion, preterm birth, and low birth weight. However, the relation of these occupational factors with fertility is less clear, the report says.
TRT World spoke to Audrey Gaskins, one of the authors of the study.