“A good laugh and a long sleep are the best cures in the doctor’s book.” Underlying this anonymous, Irish proverb there is probably truth. Most recently, the association between lack of sleep and reduced semen quality has been examined. A cross-sectional study amongst over 900, healthy young men in Denmark has associated such disturbances with diminished values in semen parameters (Am. J. Epidemiol. (2013) doi: 101093.aje/kwto49).
Those men who reported sleep disturbance as measured in a validated, sleep questionnaire demonstrated decreases in sperm concentration, total count, motility and morphologically normal spermatozoa. Equally, testis size was also diminished in the sleep-disturbed group.The greater the level of sleep disturbance, the lower the adjusted sperm concentration and the fewer morphologically-normal sperm present. (It is these normal-looking sperm that we associate with the greatest fertilizing potential).
Sleep disturbance may now be added to the line of lifestyle attributes associated with declining semen parameters. It may hold company with elevated body mass index (BMI), tobacco exposure as well as to environmental toxin exposure and atmospheric polluntants. Taken together, contributions of these environmental factors en toto, may impact fertility greatly.
The mechanism behind this new association of lack of sleep and lack of quality sperm remains unclear. It can be anticipated that further investigations will occur investigating long-term effects of sleep disturbance on fecundity and whether reversing this deprivation results in improved pregnancy rates. To quote Thomas Dekker, “Sleep is the golden chain that ties health and our bodies together.”