Mumps causes atrophy of one testicle and does not usually affect fertility as long as the other testicle is normal. If the opposite testicle also has an abnormality that prevents it from producing normal sperm, it may cause male infertility.
When the mumps virus is present, it may cause orchitis. When the infection worsens, it can lead to testicular atrophy on the affected side, which can affect the ability of the testes to produce sperm. If only one side of the testis is atrophied, the other side of the testis is functioning normally and is able to produce normal sperm, which will not affect fertility.
If the other side of the testis also has abnormalities, such as abnormal development or suffering from severe trauma, resulting in severe impairment of spermatogenic ability, it may have an impact on male fertility and may even cause male infertility.
Therefore, after suffering from mumps testicular disease, in order to avoid aggravation of the lesion, it is recommended to seek medical examination and treatment as soon as possible.