You would have to apply for a regular TRV (tourist visa).
To be approved, you will need to show you have strong ties to your home country and have no plans on remaining in Canada long term. If you say that you are coming to Canada for the purposes of giving birth, it's pretty much guaranteed the TRV will be refused.
Have you looked into the costs of giving birth in Canada? I would recommend that you budget at least $15K - although the costs could be significantly higher (even a million dollars) if there are complications.