Sandy,
Several things can cause a healthy baby not to suck when latched at the
breast:
tongue not extended at latch to pull nipple back into mouth so it rests at the
junction of the hard and soft palates (pressure here stimulates the suck
reflex.)
a high palate, or a weak tongue- again, this spot not stimulated.  Tongue
weakness can be caused by pressure on the hypoglossal nerve, this cranial
nerve passes closest to the bones of the skull (foramen magnum) on it's way
down the spinal cord, and is not unlikely to be compressed during birth...
learned helplessness or learning failure is another possibility, complementing
at the breast will assist here.
        Some tips:  have mom gently stroke under baby's chin to stimulate
sucking, gentle pressure on the tongue muscles through the chin is sometimes
enough to stimulate that tongue to do the right thing.   encourage mom to be
patient during latch on, and keep gently tickling her nipple against baby's
lower lip until the mouth is wide open AND the tongue is down and out.  This
will help get the nipple in the right place.
If none of these work, let me know.  Further observations (especially where
baby's tongue is right before and after latching on) would be helpful in
puzzling this one out.
Good luck.
Catherine Watson Genna, IBCLC  NYC  [log in to unmask]