Poor sleep linked to low total sperm count: study

In the first study of its kind, researchers found an inverse U-shaped association between self-reported sleep disturbances and sperm concentration, total sperm count and testis size among 953 young Danish men presenting for military service.

Those in the highest category of sleep disturbance had a 25% lower total sperm count and 1.6 percentage points’ fewer morphologically normal sperm compared to men with less disturbed sleep.

The authors cautioned it was a cross-sectional study