Nice wide aperture and shallow depth of field seem to be the usual choice, and for natural light you will probably need that anyway. Otherwise keep the eyes sharp and see if you can get any good facial expressions.
Aside from that, are they still in hospital? i saw a really great set on here once where several photos of the hospital itself were taken, stuff like the 'maternity ward' sign, heart rate monitors etc. All to set the scene and as a collection they really worked.