Annual patterns of human sperm production and semen quality.

Mean monthly values for ejaculate volume, sperm density, total sperm count, and percentages of progressively motile, viable, and morphologically normal spermatozoa were calculated from semen analyses performed on the husbands of all couples (excluding cases of azoospermia) referred to an Infertility Service during the years 1975-1979. No significant seasonal variations in any parameter were found. Comparison of the patterns of sperm production with other published studies indicates a tendency for increased sperm production during the late winter and early spring months.