Your visa office is Singapore. The average application takes 7 months, see http://www.cic.gc.ca/english/information/times/international/05-fc-spouses.asp#asia That would be after you are approved as a sponsor by Mississauga and your file sent to Singapore. You can try to contact them and ask but you are still within the normal timelines so there is no need to worry. You can advise them that your wife is pregnant. Maybe it will speed things up, who knows.
If your wife gets the PR visa only after she is too pregnant to travel anymore, then you will have to.. a) if you are a PR, do what ariell says and add the baby when it's born to your application to sponsor it for PR or b) if you are a citizen, apply for a citizenship certificate for the baby and a temporary passport.