Toni
I don't have any references but I'll give you my personal experience and
theory.  You hear that newborns are alert for the first hour or so and then
fall into a long, deep sleep.  I don't believe that this is normal.  I think
they fall asleep after that first hour because of overstimulation ( bright
lights, rough towels, suction, bathing, eye drops, Vit. K injection etc. ).
 I think the kids just shut down from being utterly overwhelmed.  On a
personal note, my second baby was born in a hospital but it was a totally
natural birth, no meds nothing "stuck" in me, I arrived only an hour before
she was born (stayed at home for 12 hours even with ruptured membranes).  She
was born then put to breast, it was late at night and I opted to not have her
bathed or anything until the next morning (she wasn't dirty).  She never
slept the whole night.  After a few hours of breastfeeding and overwhelming
contractions I put her in her bassinette and pulled her up against my bed.  I
tried to sleep, and though she was very quiet, my little baby stayed awake
and looked around the dark room all night.  She was so alert for hours!
Again, just anecdotal but I feel important,
Chelle Goodfriend, IBCLC, Anaheim Hills, California