A woman giving birth? What kind of analogy is this? Does she know who the father is? Does she have a support structure? Who is she giving birth to? Are you just looking for an analogy for a painful process which has to happen?
Sounds to me like you’ve no idea about the variables of the birth process. Seriously, Michael, stick to what you know. Maybe use a man who has awful constipation, with a boulder in his bum, trying to take a shit.
Or maybe abandon analogies altogether. This one isn’t working for you.