Charlie, you post that as if there is something negative about it, unless I misunderstand. There is a big difference between the concept of immodest behavior and the concept of untzniusdig behavior. Though it is true that a woman giving birth is baring all in that delivery, she is NOT being untzniusdig, though her personal modesty is being compromised. She is doing exactly what Hashem created her to do, and she is fulfilling a mitzvah. Would anyone say that is negatively immodest? Untzniusdig behavior involves actions that are unquestionably NOT l’shem Hashem.
BTW, when most women are giving birth, I can absolutely guarantee that the LAST thing they are thinking of is anything to do with modesty. They just want that baby OUT!!!!!!!!!!!