Rashbam's twist on a famous story

Bava Basra 120a. The gemara tells the famous story of Yocheved, the mother of Moshe Rabeinu being delivered "Bein Hachomos," as Yaakov and his family enter Mitzrayim. The traditional story is that she was born as they were walking through the wall. For women who have given birth, imagining this story as commonly told is both difficult and maybe even inspiring. The Rashbam though defines that Yocheved was conceived outside of Mitzrayim, but only the she came to Mitzrayim (Bein Hachomos) in her mother's womb, but that she was born in Mitzrayim. The gemara he says is only figuratively balanced in he conception "baderech" as it is figuratively birth "Bein Hachomos."