SDCL § 43-3-14: Limitation of future interest to successors, heirs, issue, or children--Rights of posthumous children.

If a future interest is limited to successors, heirs, issue, or children, any posthumous child is entitled to take in the same manner, if the child was conceived prior to the decedent's death, was born within ten months of the decedent's death, and survived one hundred twenty hours or more after birth.