Read more: Celeb couple takes baby boy, Saint West home

Robert, who died in 2003, would have been 72 years today. "Today is my dad's birthday. I know there's nothing more in the world he would have wanted than to meet his grandchildren. So I wanted to share this picture of Saint with you all," she wrote on her website.

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Kardashian and Kanye West welcomed their second child on Dec. 5, 2015.

The celebrity baby, Saint was sleeping soundly with his arms raised above his head wearing a cozy white onesie.

Read more: Reality star shares cute photo of North West in her closet