N.H. Rev. Stat. Ann. § 168-B:3

If, under the provisions of this chapter, a parent-child relationship is created between 2 persons, the child shall be considered, for all purposes of law, the legitimate child of the parent. In the absence of specific language to the contrary in a statute or instrument, a legitimated child shall be considered the same as a birth child, issue, or heir of the body for all purposes of the law.