Study links shift work to potential fertility problems

Istanbul — A recent study involving female mice shows that only four weeks of shift work-like light patterns were enough to disrupt their biological clock and reduce fertility.

A team led by French researchers mimicked long-term shift work conditions for the mice “by constantly shifting the light-dark cycle, delaying and advancing light exposure by 10 hours across four weeks.” Findings show that the massive release of the pituitary hormone called luteinizing hormone – which triggers ovulation – was terminated, reducing fertility.

“The decreased fertility is due to an alteration of the master circadian clock signaling toward the hypothalamic reproductive circuit,” lead researcher Marine Simonneaux said in a press release. “Specifically, our research shows that four weeks of chronic shift exposure impairs the transmission of light information from the master biological clock to the kisspeptin neurons, known to drive the timing of the pre-ovulatory luteinizing hormone surge.”

The researchers say their findings could help scientists understand how disturbances in circadian rhythm can affect female fertility and eventually lead to future prevention strategies for women who work nonstandard schedules.

“Understanding the precise mechanisms by which circadian disruption alters the reproductive function is important, as it may pave the way for potential preventive and therapeutic interventions to reduce some of the negative effects of shift work on women’s fertility,” Simonneaux said.

The study was presented at the 25th European Congress of Endocrinology.