new born outside usa of lpr

[green card 2013]

hello,my case was completed and forwarded to my original country at nvc and im waiting for interview,my husband is a green card holder and i was trought f2a process ,my baby will born before interview
1-how can baby be added to my petition and case completed and all documents already forwarded to my consulate ??
2-what documents should i submit in this situation??
3-how much time take this process?
4-will nvc change my interview date until finishing paper of my new born?
thanks.