What constitutes a normal seminal analysis? Semen parameters of 243 fertile men

A cross-sectional study was conducted to determine the semen parameters (i. e. volume, concentration, motility, viability and normal morphology) of pro ven fertile males in Singapore and compare it with the World Health Organiz ation (WHO) recommended normal values and to examine some factors that may affect spermatogenesis, A total of 243 men, whose wives were pregnant at th e time of collection of semen, provided a semen sample each after sexual ab stinence for 3 days. A questionnaire was used to elicit occupational exposu re, alcoholic consumption, smoking history and past significant medical his tory, Most subjects had normal sperm volume (56.4%), concentration (79.8%), motility (69.5%) and viability (53.5%) based on WHO criteria. However, fer tile men had a low mean percentage of normal sperm morphology (20.0%), alth ough they were normally distributed. Cigarette smoking was associated with significantly lower semen volumes even after adjusting for alcohol consumpt ion. The sperm parameters (i.e. volume, density, motility, viability and no rmal morphology) were not significantly associated with ethnic differences, The WHO criterion for normal sperm morphology is too stringent, and should be adopted with caution. Normal sperm morphology is but one of many parame ters for assessment of fertility. Social alcohol consumption, cigarette smo king, and 'recent fever' did not appear to affect sperm quality in this gro up of fertile men.