the first 6 weeks i take a proper maternity leave - although with dd2 i was working on day 3 while she was sleeping but from home, and after 3 weeks my bum hurt from sitting on the floor (no office desk at home just low coffetable) so went to the office
we work in a company that makes baby products so it is more understandable than if i worked at a male grooming product firm...
about the work hours, it depends on they baby. with dd2 i worked 3/4 days until she was 4 months old, and then when she was too awake and i had to get back to working full days, i started going in to the office most days without her.
with dd1 i used to work in an office where my sister and mil worked and they would babysit and share the baby entertaining with me so i kept her there for about 8 months!
now i also have dh who can take dd3 some of the time.
if you work efficiently, you can get about 75% of your job done in 50% of the time, or less, when it gets too much, its time to go back to work full time and leave the baby at home....