Some studies have shown that male patients with chronic C virus have significant decrease in sperm count, semen volume and progresive sperm motility, which is neccessary for natural conception. Also in compare to healthy men, they have higher level of abnormal sperm morphology. Some of these men have lower serum of testosterone which leads to lower sperm production.
Chronic hepatitis C infection can change the reserve of preantral follicles. Preantral follicles are cells which are predecessors of eggs. Decreased count of follicles leads to less ovulations, thus there is lower possibility of natural conception due to absent egg which can be fertilized.