I have three questions, but they are all related closely.
There appears to be a minhag (widespread among Ashkenazi women) that after childbirth, the first place the yoledes (woman who has given birth) goes must be the Shul, and she may not go elsewhere first. Does anyone know a Mekor for this?
My theory is this is a conflation of two other customs. Firstly, that (in the diaspora at least) a mother goes to Shul to hear her husband receive an Aliya, to discharge her duty to bench Gomel (as nowadays women do not bench Gomel in public). And secondly, that (per Gemora Berachos 54b) a Yoledes requires Shemira for the first few days after birth. I conjecture that these two points were combined to create an erroneous belief that one may not leave the house except to go to Shul. Has anyone heard anything about this?
The Gemora I mentioned above regarding Shemira for a Yoledes does not appear to be codified by the mainstream Poskim. Nor is it defined, e.g. how many days does it last. Can anyone elaborate or identify a Mekor for this?