Subject to subsection (b) of this section, a juvenile court shall rule on the adoption petition under this Part IV of this subtitle promptly but no later than 180 days after the petition is filed. A juvenile court may not enter an order for adoption of a child under this Part IV of this subtitle before the later of: 30 days after the birth of the child; or 10 days after the notice is served under § 5-346 of this subtitle.