Missouri Revised Statutes Title XXX. Domestic Relations § 453.040. Consent of parents not required, when

(1) A parent whose rights with reference to the child have been terminated pursuant to law, including section 211.444 or section 211.447 or other similar laws in other states;

(2) A parent of a child who has legally consented to a future adoption of the child;

(3) A parent whose identity is unknown and cannot be ascertained at the time of the filing of the petition;

(4) A man who has not been established to be the father and who is not presumed by law to be the father, and who, after the conception of the child, executes a verified statement denying paternity and disclaiming any interest in the child and acknowledging that this statement is irrevocable when executed and follows the consent as set forth in section 453.030;

(5) A parent or other person who has not executed a consent and who, after proper service of process, fails to file an answer or make an appearance in a proceeding for adoption or for termination of parental rights at the time such cause is heard;

(6) A parent who has a mental condition which is shown by competent evidence either to be permanent or such that there is no reasonable likelihood that the condition can be reversed and which renders the parent unable to knowingly provide the child the necessary care, custody and control;

(7) A parent who has abandoned a child as described in paragraph (b) of subdivision (2) of subsection 2 of section 211.447 or paragraph (b) of subdivision (1) of subsection 5 of section 211.447;

(8) A parent whose rights to the child may be terminated for any of the grounds set forth in section 211.447 and whose rights have been terminated after hearing and proof of such grounds as required by sections 211.442 to 211.487. Such petition for termination may be filed as a count in an adoption petition.