Seasonal variations and age-related changes in human sperm count, motility, motion parameters, morphology, and white blood cell concentration.

OBJECTIVE: To determine the presence of any seasonal variations and age-related changes in sperm parameters in andrology patients and fertile donors.
DESIGN: Retrospective analysis.
SETTING: University medical center andrology laboratory. PATIENT(S): The database of 2,065 semen analyses was retrospectively reviewed for the period of March 1, 1996, to October 31, 1998. INTERVENTION(S): None. MAIN OUTCOME MEASURES(S): The sperm count, motility, motile count, progressive straightline velocity, and percentage of rapid sperm were determined with the Hamilton-Thorne IVOS analyzer with standard setup parameters. RESULT(S): There were no significant seasonal differences in the patient's volume, sperm count, motility, motile count, whereas the percentage of rapid sperm and progressive straightline velocity were significantly lower in the spring. Correlation analysis of patient semen parameters versus age implied that as age increases there is a tendency for these semen parameters to decrease, whereas percent tail defects showed a significant positive correlation with age. CONCLUSION(S): Age-adjusted analyses of seasonal variations in andrology patient semen parameters showed significant seasonal variation in the percentage rapid motile sperm and straightline velocity, as well as the percent tail defects, percent immature sperm, and the percent tapered sperm. Such seasonal variations might prove to be clinically relevant and important when designing experimental protocols.