Hi, you can go ahead and update AVO now with the birth of your child by CSE, https://secure.cic.gc.ca/enquiries-renseignements/case-cas-eng.aspx?mission=accra
Ensure you attach the birth certificate to the CSE and begin to process the child's international passport, additional FSW application fee to cover the child and new POF for your new family size ahead of when AVO will fire you their "welcome baby" mail
Please extend our regards to your madam on the successful down load of the future Canadian.