If a wife happens to be pregnant at the time of the death of her husband, no tutor shall be appointed to the child till after his birth; but, if it should be necessary, the judge may appoint a curator for the preservation of the rights of the unborn child, and for the administration of the estate which may belong to such child. At the birth of the posthumous child, such curator shall be of right the undertutor.
La. C.C. § 252