The penalty provided for parricide in Article 246 and for murder in Article 248 shall be imposed upon any person who shall kill any child less than three days of age. If any crime penalized in this Article be committed by the mother of the child for the purpose of concealing her dishonor, she shall suffer the penalty of prision mayor in its medium and maximum periods, and if said crime be committed for the same purpose by the maternal grandparents or either of them, the penalty shall be reclusion temporal.