S.D. Codified Laws § 43-3-14
Current with legislation signed by the governor on or before 3/6/2024
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.
SDCL 43-3-14