This is a grievous sin, a form of castration. Consciously choosing sterilization is a grave sin, as it goes against the meaning of the sexual act that God created. It contradicts God's plan, wisdom, and design, and thus it is a serious sin that must be repented.
The person must sincerely repent of this sin and, when medically possible, should seek to reverse the surgery or procedure. This is very important. If it is not possible to reverse the procedure, they must ask the Lord for strength to live in abstinence, as their action was against the order of God.
By making themselves consciously sterile, they have chosen an act contrary to God's will. If they wish to live a true Catholic Christian life, they should ask the Lord for the strength to live according to His law, even in this area. They should avoid actions that are intentionally sterilizing, as these are contrary to God's will.
