parents during pregnancy

Hi,

I am expecting my baby in july and want my parents to come over for delivery, iam not working currently(l2 visa).. I have few questions about the tourist visa.. hope to get help from here:

1 What documents do we need to send them and what docs should they carry from their side( indian bank statemnts , property docs etc)

2 i have read that we should not mention pregnacy as reason, what should they answer if asked explicitly that is your daughter pregnant? in case they dont mention pregnancy, we are planning to bring my mil too after my parents leave .. will that be a problem later for her visa ?

3 they are funding themselves for tickets and all expenses .. should we mention that somewhere?

4 on whose behalf should we send the invitation letter(my dh or me)?

please help me with this .. this is their first visit and iam really confused