Hey,
I've taken a year off between finishing med school and starting residency. Does it effect the position you get? Will tell you once the match is done. It won't effect your interviews; you will get good ones. In your case, you have an extremely good reason for delaying the commencement of your training. You should be fine, the time off for you will be inconsequential. I was denied interviews at a few top programs because I took time off, but thems the brakes. You can only live life once...live it on your own terms.
take the time off...YOU WILL REMEMBER BEING WITH YOUR BABY FAR LONGER THAN YOU WILL THE ONE YEAR DELAY OF RESIDENCY.