News | How Night-Shift Work Disrupts Women's Body Clocks and Affects Fertility
A study presented at the 25th European Congress of Endocrinology found that just four weeks on a night-shift-like schedule disrupted the body clocks of female mice and significantly reduced their fertility. The finding deepens understanding of how circadian disruption affects female fertility and points to new research directions for improving the health of women who work night shifts.
Circadian rhythms and female fertility
Circadian rhythms are regulated by the body's internal clock, primarily in response to changes in light, and follow a 24-hour cycle. The body clock regulates many essential functions, including the sleep-wake cycle, hormone secretion, digestion, and reproduction. Inappropriate light exposure, such as light at night, can readily disrupt this balance.
The body's master clock is located in the suprachiasmatic nucleus (SCN) of the hypothalamus. The hypothalamus not only controls the body clock but also regulates reproduction through the pituitary gland, which in turn controls ovarian activity and ovulation. Many studies show that circadian disruption negatively affects female reproductive capacity, although the exact mechanisms are not fully understood.
Methods and key findings
Researchers from the University of Strasbourg and the Institute of Cellular and Integrative Neurosciences in France simulated the light environment of long-term night-shift work. Female mice underwent four weeks of inverted light-dark cycles, with light exposure shifted by 10 hours.
The study found:
Reduced luteinizing hormone release: Circadian disruption impaired the pituitary gland's ability to release luteinizing hormone (LH), the key hormone that triggers ovulation.
Impaired reproductive function: Disrupted signaling from the master clock to reproductive circuits in the hypothalamus reduced ovulation and significantly lowered fertility.
The team further noted that interrupted light signaling primarily affected kisspeptin neurons in the hypothalamus, which play a key role in timing LH secretion.
Future research
Lead researcher Dr. Marine Simonneaux said the next step is to examine whether circadian disruption affects other internal clocks. Besides the master clock, many secondary clocks are located in other brain regions and peripheral organs, including the reproductive organs. Their synchronized activity is essential for normal reproductive function.
Dr. Simonneaux noted that understanding how circadian disruption alters reproductive function will support the development of preventive and therapeutic measures to reduce the effects of night-shift work on female fertility.
Significance and clinical implications
The study offers important insights for managing the health of women who work night shifts. Because many women worldwide work nonstandard hours, including healthcare and factory workers, the findings emphasize the importance of managing schedules and reducing light exposure at night. Targeted interventions may eventually reduce the effects of circadian disruption on female fertility.
News | How Night-Shift Work Disrupts Women's Body Clocks and Affects Fertility
News | How Night-Shift Work Disrupts Women's Body Clocks and Affects Fertility
A study presented at the 25th European Congress of Endocrinology found that just four weeks on a night-shift-like schedule disrupted the body clocks of female mice and significantly reduced their fertility. The finding deepens understanding of how circadian disruption affects female fertility and points to new research directions for improving the health of women who work night shifts.
Circadian rhythms and female fertility
Circadian rhythms are regulated by the body's internal clock, primarily in response to changes in light, and follow a 24-hour cycle. The body clock regulates many essential functions, including the sleep-wake cycle, hormone secretion, digestion, and reproduction. Inappropriate light exposure, such as light at night, can readily disrupt this balance.
The body's master clock is located in the suprachiasmatic nucleus (SCN) of the hypothalamus. The hypothalamus not only controls the body clock but also regulates reproduction through the pituitary gland, which in turn controls ovarian activity and ovulation. Many studies show that circadian disruption negatively affects female reproductive capacity, although the exact mechanisms are not fully understood.
Methods and key findings
Researchers from the University of Strasbourg and the Institute of Cellular and Integrative Neurosciences in France simulated the light environment of long-term night-shift work. Female mice underwent four weeks of inverted light-dark cycles, with light exposure shifted by 10 hours.
The study found:
Reduced luteinizing hormone release: Circadian disruption impaired the pituitary gland's ability to release luteinizing hormone (LH), the key hormone that triggers ovulation.
Impaired reproductive function: Disrupted signaling from the master clock to reproductive circuits in the hypothalamus reduced ovulation and significantly lowered fertility.
The team further noted that interrupted light signaling primarily affected kisspeptin neurons in the hypothalamus, which play a key role in timing LH secretion.
Future research
Lead researcher Dr. Marine Simonneaux said the next step is to examine whether circadian disruption affects other internal clocks. Besides the master clock, many secondary clocks are located in other brain regions and peripheral organs, including the reproductive organs. Their synchronized activity is essential for normal reproductive function.
Dr. Simonneaux noted that understanding how circadian disruption alters reproductive function will support the development of preventive and therapeutic measures to reduce the effects of night-shift work on female fertility.
Significance and clinical implications
The study offers important insights for managing the health of women who work night shifts. Because many women worldwide work nonstandard hours, including healthcare and factory workers, the findings emphasize the importance of managing schedules and reducing light exposure at night. Targeted interventions may eventually reduce the effects of circadian disruption on female fertility.
Source:
Collected online