California Code, Family Code - FAM § 8815

(a) Once the revocable consent to adoption has become permanent as provided in Section 8814.5, the consent to the adoption by the prospective adoptive parents may not be withdrawn.

(b) Before the time when the revocable consent becomes permanent as provided in Section 8814.5, the birth parent or parents may request return of the child. In that case the child shall immediately be returned to the requesting birth parent or parents, unless a court orders otherwise.

(c) If the person or persons with whom the child has been placed have concerns that the birth parent or parents requesting return of the child are unfit or present a danger of harm to the child, that person or those persons may report their concerns to the appropriate child welfare agency. These concerns shall not be a basis for failure to immediately return the child, unless a court orders otherwise.