If the child is born after you receive Permanent Residency, of course your child would be inclided! If the child is born before the I-526 is filed, then the child is added to the petition as a derivative beneficiary. If the child is born after I-526 approval and before applying for permanent residency, the NVC can be notified of the new addition and send the immigrant visa invoice for the baby.
Based on the facts you present your child may apply for conditional permanent residency through the US consulate especially if the child is born in your home country before you,your spouse and the rest of the family apply for the conditional permanent residency visas at the U.S. consulate. However, the good news is that if your wife is in the United States after you and your spouse and the rest the family have obtained your conditional status and the child is born in the U.S. then the child will become a U.S. citizen.