Varicocele does not always lead to infertility; varicocelectomy does not always improve sperm. The study objective: to evaluate the quantitative correlation between varicocele and reproductive function with a large sample. Design: a cross-sectional and case control study. Materials and methods: 3632 patients from infertile couples and 276 fertile males. The ejaculate was tested following WHO recommendations (2010), DNA fragmentation was evaluated with chromatin dispersion in agarose gel. Results: we found weak correlation between varicocele degree (VD) and the spermogram parameters: -0.11 for concentration (р<0.001), -0.08 for progressively motile sperm count (PMSC) in the ejaculate (р<0.001), 0.11 for DNA fragmentation (р<0.01), correlation with other parameters was insignificant (p>0.05). The clinical varicocele (V) prevalence in the fertile (F) and the infertile (I) males was the same: 27.2% (75/276) in the F, 31.4% (101/322) in the I1 with oligoasthenotertozoospermia (OAT) syndrome, 34.4% (43/125) in the I2 with OAT (p>0.05). In the general sample of the males from infertile couples V was found insignificantly more frequently in the I2 than in the I1 31.6% (426/1348) and 28.1% (641/2284), respectively (OR=1.13; p<0.05), because of degree 1 varicocele: 23.5% и 20.2%, respectively (OR=1.16; p<0.05). Compared to the males without varicocele, median concentration is 8 mln/ml less in degree I,17mln/ml in degree II and 24 mln/ml in degree III (p<0.001); we found parallel increase in oligozoospermia rate: from 14% without varicocele to 27 and 26% in degree II and III (p<0.05-0.01). The PMSC in degree I varicocele is 10 mln less (-16% of the group without varicocele),in degree II 27 mln less (-44%), in degree III 23 mln less (-38%) (р<0.001); the difference between the groups with degrees II and III is insignificant (p>0.05). The DNA fragmentation was significantly lower only in degree III (p<0.05). We found no difference in the sperm motility and morphology among the groups (p>0.05). Conclusion. In varicocele, the sperm count decreases but in ¾ of cases, concentration is within reference values; there is no difference between degree II and III. The sperm motility and morphology do not depend upon varicocele. The DNA fragmentation is increased in degree III varicocele. The relative risk of infertility in varicocele is low (OR is ≤1.13).

Keywords: astenozoospermia, DNA fragmentation, spermogram, teratozoospermia, oligozoospermia, male infertility, varicocele