A Comprehensive and Systematic Study of Semen Quality and Sperm Functional Status in Normozoospermic Controls and Infertile Males from South India

Abstract

Objective: Despite, several global studies indicate the variations in semen characteristics that accounts for male infertility, the association of specific changes in semen quality and fertility status among different Indian communities are poorly investigated. With wide range of geographical locations, diverse lifestyle patterns, seasonal variations combined with heterogeneous population, India offers an excellent system to study genotype-to-phenotype correlation. Hence, the current study has been initiated in South Karnataka region of India, in order to examine the variations in semen quality and sperm functional status in infertile individuals compared with normozoospermic controls.Methods: WHO strict guidelines are followed for systematic semen analysis of 239 infertile and 244 normozoospermic control subjects.Results: Interestingly, compared to normozoospermic controls, higher percentage of physical abnormalities such as, low semen volume and reduced sperm count are observed in infertile men. Additionally, semen characteristics namely, vitality and motility values are significantly reduced in infertile than controls. Further, in sperm function test the lower scores are documented for hypo-osmotic swelling assay, but not for sperm chromatin decondensation and acrosome intactness examination, suggesting loss of sperm plasma membrane integrity in infertile men. Moreover, the observed changes in semen parameters and sperm function are also evident in different infertile sub-conditions with varied responses. Surprisingly, age wise analysis revealed reduction in sperm morphology scores, whereas, vitality, count, motility and volume remain unchanged with increasing age of infertile males. However, we recorded inverse relationship between age and sperm vitality as well as motility in normozoospermic control men. Together, though the scores for different semen parameters in normozoospermic control group are in accordance with WHO reference range, the infertile men displayed poor semen quality. Conclusion:Thus, our data establishes basic differences between infertile and normozoospermic control group in terms of semen characteristics and sperm functional status, but the cause may be attributable to genetic or environmental factors or interaction of the two, which necessitates further detailed examination in larger cohort among heterogeneous population.