Consent of a parent to adoption shall not be required if a decree of termination with regard to such parent has been entered. When parental rights have not previously been terminated, the court may find that consent of a parent of the adoptee is not required if, after notice and hearing as prescribed in section 2513 (relating to hearing), the court finds that grounds exist for involuntary termination under section 2511 (relating to grounds for involuntary termination).