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.