Existing evidence suggests that a woman’s daily sleep-wake cycle can affect her menstrual cycle.
For example, working night shifts and frequently traveling across time zones has been associated with menstrual irregularities, reduced fertility and a greater number of negative pregnancy outcomes like low birth weight, preterm birth and miscarriage.
Furthermore, by removing the brain’s regulator of daily circadian rhythms, female mice become infertile. Now new research further supports the link between sleep patterns and fertility.
A research group out of Northwestern University found that by changing the normal sleeping patterns of mice, they could decrease the rate of pregnancy.
The “daytime” period was altered for different groups of mice by changing the times when the lights were turned on in the lab.
The researchers found that the rate of full-term pregnancy decreased with increasing sleep-pattern irregularities from 90% down to 22%.
Because the effect seemed to prevent pregnancy and not terminate an established pregnancy, the authors believe that sleep-pattern irregularities may affect embryo implantation.
The authors caution that these experiments were performed in a mouse model, which have different reproductive cycles than humans. However, fertility experts recommend women who are trying to conceive should maintain regular sleep cycles.