Most males with a varicocele have no symptoms. But varicoceles are a concern for many reasons. Some may cause infertility (problems fathering a child) and slow growth of the left testicle during puberty. Varicoceles may be the cause of fertility problems in about 4 out 0f 10 men who have problems fathering their first child. They may also be the cause of fertility problems in about 8 out of 10 men who have problems fathering a child after their first.