I had two cats (only have one now) and from my experience, when I brought my kids home from the hospital, they have wanted nothing to do with the squirmy loud human type thingy and kept well clear. I have never made any allowances for them, nor have I cat proofed my kids and house, nor have I kid proofed my cats etc...
The midwive will not have anything to say about your having pets, nor will the health visitor, they won't even ask you about it. Its none of their concern. They do check to make sure you aren't suffering from ppd, and that there are any child protection issues for them to be concerned about. They won't care if you have cats or not.