Hello!
Your child will be Canadian, in need of their Canadian Birth Certificate if you are a 'first generation' Canadian yourself.
So, if you were born in Canada (edit, or BECAME a Canadian as per the website), that child is Canadian. If you were born to Canadian parents outside of Canada, you will be needing to sponsor your child to this fair country.
As it stands, your child's children will need to be born in Canada to be Canadian, otherwise if they are born outside of the country, they will be also in need of sponsorship.
Here's the website showing:
cic.gc.ca/english/information/faq/citizenship/index.asp
Under the question, "What does limiting Canadian citizenship to the first generation born to Canadian parents outside Canada mean?"
Cheers~