Dear Sohail: Although you don't mention it, should we assume that from the job offer you ALREADY possess the entry visa for you and your wife? If so, there should be no problem for the new child.
However, if you only have the job offer and no visa, I'd say your trek may still be uphill. If your job offer is from a highly skilled sector (which I am hoping), your chances are good for the whole family. Don't forget to buy medical insurance for everyone, especially the baby, since even as landed immigrants, gov't. health insurance is only available after 3 months of residence, which you will prove upon application at the provincial health care office. Show the entry stamps into Canada, pay stubs, bank statements etc...anything with your name and address.