Not sure whether this research is lip and palate but it's worth a try.
Both articles are in a journal called Plastic Reconstructive Surgery.
Weatherly-White etal Early repair and breastfeeding for infants with cleft lip.
79;879 1987
Fisher J.C. Early repair and breatfeeding etc. 79;886 1987
I remember the sensible attitude of the surgeon that breast tissue was the least damaging way of delivering milk to a recent repair.
Jenny James B.A. Nurs. R.N. ,IBCLC currently in Kuala Lumpur.