(a) Consent shall be in writing and shall be acknowledged before a judge of a court of record or before an officer authorized by law to take acknowledgments. If consent is acknowledged before a judge of a court of record, it shall be the duty of the court to inform the consenting person of the legal consequences of the consent. A consent is final when executed, unless the consenting party, prior to final decree of adoption, alleges and proves by clear and convincing evidence that the consent was not freely and voluntarily given. The burden of proving the consent was not freely and voluntarily given shall rest with the consenting party.

(b) Consent in all cases shall have been executed not more than six months prior to the date the petition for adoption is filed.