an explanation that i heard goes as follows: in China villages, the water comes from rivers and wells, which will have bacterias and other contaminations. so for folks in the past, can't bathe with that water after pregnancy to avoid infections. water can also be scarce and precious.
and as Alaska said, it can be very cold in China.
however, if we blindly follow, and do the same things in Singapore, where it is hot and humid all year, and where the water is clean, it doesn't seem to make any sense.
tell this to ang moh from USA or Australia etc, and they will laugh until peng.
think I actually mentioned about the confinement thingy to a Australian woman when I was staying with her... told her about what la the wind thing that might get to the woman when she bathes and must eat wat type of food la... ya lor.. she really laugh until Peng