Does anyone know where I can look to get information about what qualifies a woman for early, paid, medical leave from work (up to 17 weeks)? I can not seem to find a decent website about it.

I see you aren't in the US - so I can't help you I am afraid - move to the US and I can

You should be able to just go to the place that offers you the paid leave ie either work or your type of government that offers pensions and see what they need for you go to on leave..
In Aus, we need a letter from the doc stating that it is no longer possible for this person work because of blah blah blah...
Goodluck with it!

I was recently looking into this as I've been signed off work for 4 wks and probably wont return back until my maternity leave starts at 36 wks.

What do you want to know? The DWP's site had some information about it.

citizens advice?

All I want to know are the conditions that are listed to enable early leave. I am finding the boss at work very stressful and it is only going to get worse. I know other people that have gone off on it but I did not know the various condition that where listed to be able to go off early.

I look forward to more of your advice.

Thanks

Your doctor signing you off is all you need! If it be physical or stressful he/she may sign you off. Is that what you mean? What ever your doctor signs you off for qualifies!!