Here is how i understand this situation
you dont have to inform CIC if you get pregnant, but you have to inform them when your baby is delivered. so if you get a baby before you land , you will have to apply for your baby separately.
Also bear in mind that post ITA you would need to get a medical done, and X-ray is part of the medical exam and you cant get an X-ray done when you are pregnant, (its not safe for the baby, that what doctors say). so if you cant get medical done after ITA your PR application will be delayed in any case.