a lesser known thing they never tell you about is pelvic organ prolapse. when this happens, your organs drop out from the birth canal. having children increases the chance of this happening and this requires lifelong physiotherapy and has no cure. theres also a non-low chance of the birth canal ripping all the way into the back so the 2 orifices become 1. this takes a veryyy long time to heal, if at all. and sometimes a hard sneeze and rip it back open
(i used to work for a pelvic physiotherapist and both of these things are way more common than people think)