

Reading to a baby is about exposing them to different words and patterns than what you get from normal speech.
If you want my advice, talk to them constantly as if you are the narrator, and smile and make eye contact at every opportunity.
Not sure if this applies before birth. It couldnt hurt, so I suggest reading whatever you like to read. And make sure its something that the mother wants to hear, assuming you arent her.
I bet they dont check. Yo quero taco bell? Hired.