Definite contraindication for bag and mask ventilation is:
c. Congenital diaphragmatic hernia(Ref: AAP guidelines 2015, Ghai 8/e p 126-133)Bag & mask ventilation should be avoided in Congenital diaphragmatic hernia, because it enlarges the stomach and small bowel and thus makes oxygenation more difficult.
Cleft lip
Cleft palate
Congenital diaphragmatic hernia
Umbilical hernia
New Born Infants