Is a young man considered infertile due to an old injury to the scrotum, or a previous practice of masturbation, or a slight curvature in the penis?

The majority of scholars hold that the defects warranting annulment are those that prevent intercourse or are repulsive and contagious diseases. However, some scholars, such as Ibn Al-Qayyim and Ibn Uthaymeen, believe that any defect that frustrates the purpose of marriage—such as infertility—necessitates disclosure, because it prevents procreation, which is one of the most important objectives of marriage.

Therefore, if you are medically confirmed to be infertile, it is best to inform the woman you propose to in order to avoid conflict. Imam Ahmad and Ishaq ibn Rahawayh supported this view to prevent gharar (deception/risk).