The scene of Aaron's birth from episode #1.20 Do No Harm (2005) was reused for this episode including archive footage of Emilie de Ravin as Claire Littleton and additional material with a stand-in.
Jack tells Sayid he was unconscious for over 42 hours. 42 is one of the island's "numbers".
Ben tells Jack to meet him at the marina, slip 23. 23 is one of the island's "numbers".
When Sayid questions the killer orderly about who is trying to kill him, the orderly tells him to look in the orderly's pocket. The address on the piece of paper that Sayid pulls out turns out to be Kate's address. Kate's house number is "42", which is part of the mythical island "numbers."
The name of the French expedition's lost boat is "Bésixdouze", which means B612 In the book "The Little Prince" by Antoine de Saint-Exupéry, the title character lives on Asteroid B-612.