9. Extension of certification. When a petition for adoption is filed by a qualified parent or parents previously certified and the balance of the time period remaining under such certification in accordance with subdivision six of this section is less than one year, the court may on its own motion or on the motion of the petitioners extend the time period of the original certification to a date eighteen months from the date of filing of the adoption petition. When a petition for adoption is filed by a qualified parent or parents who have previously been certified by an order which has expired within a year preceding the date of the adoption petition, the court may extend the termination date of the earlier certification until eighteen months from the filing of such petition, provided the petitioner apply for such extension and set forth any change of circumstances of the qualified parent or parents since issuance and expiration of the last certification which may be relevant and material to the extension of such certification and affix thereto written verification of any such changed circumstance or lack thereof by a disinterested person as defined in subdivision four of this section. Except as is provided for by this subdivision, the court shall not extend a previously expired order of certification. Any further certification shall require the filing of a new petition for certification in accordance with subdivision six of this section. In any instance when the court determines whether to extend a certification under this subdivision, the court, in its discretion, may order each or any of (a) a report from the statewide central registry of child abuse and maltreatment to determine whether the child or the petitioner is or has been the subject of or another person named in an indicated report, as such terms are defined in section four hundred twelve of the social services law, filed with such register, (b) a report from the division of criminal justice services setting forth any criminal record of such petitioner or petitioners, and (c) an additional pre-placement investigation to be undertaken by a disinterested person. Nothing herein shall be deemed to require that the court enter such an order.