I have no experience with introducing babies to cats and vice versa, since by the time Midnight joined the family, my kids were between the ages of 5 and 15. Instead, I'll address the sentence/question above.
Pregnant women are generally asked to not clean the litterboxes due to something called toxoplasmosis. However, if a pregnant women wears gloves, washes her hands thoroughly, and maybe use a bit of hand sanitizer, the risk of getting it is pretty low. Most doctors still recommend that pregnant women not clean the litterbox just to be safe.