Objectives: Quality of semen is one of the most important factors contributing to couples' chance of natural conception. There are many confirmed or potential factors that influence semen analysis results.

To estimate the incidence and analyze male factor infertility.

Material and methods: The retrospective observational study was in the Clinical Department of Gynecological Endocrinology and Gynecology, University Hospital in Krakow. The study included men from subfertile population, aged ≥ 18 years, without prior diagnosis and obvious cause of infertility, whose initial seminograms were used to characterize the population. Seminograms of men remaining in the follow-up were used to analyze the variability of sperm parameters in relation to lifestyle modification and the use of fertility supplements containing antioxidants. Control semen tests were performed at 1-3-month intervals.

Results: The study included 870 men. In 68.5% of men, at least one abnormal sperm parameter was found and 40.7% had complex sperm abnormalities. Averaged values of sperm parameters of men from subfertile couples were within the WHO reference ranges, except for the normal morphology, whose median was 3.8%. No significant differences in the selected sperm parameters after the implementation of conservative management were observed. The percentage of pregnancies not resulting from IVF in the follow-up population was 7.7%.

Conclusions: One semen sample is representative of an individual in the diagnostics of male infertility. Expectant management and lifestyle modification should not be proposed as first-line treatment when more effective procedures are available.