Also, please note that the marraige certificate and birth certificates of the parents must be attested by the state and central governments in India (atleast this was mandatory in Zurich). you have to submit the attested documents in the zivilstadsamt in the place where your child is born and the swiss authorities in most cases do an independent verirfication of your documents by a third party agency. this means somebody from Swiss embassy may come to your home in India and verify the facts given by you in the application.so if this is your first child born in Zurich, then it is very time consuming. atleast we got our daughter's birth certificate when she was 8 months old. in our case, we submitted our documents late around 3 months after the birth(we are on B permit by the way).

cheers
happycreature