What is a congenital deformity or malformation?

Abnormal birth: Any abnormality in the baby is considered a malformation. It can be as simple as an extra digit or as severe as multiple malformation syndromes that can be lethal to the newborn.

Terminology issue: Malformation implys that the tissue or organ involved did not follow the normal pattern, like a cleft lip or palate, or heart defect. Deformity implies the distortion of normal tissue/features by an external event. Abnormally shaped feet, legs,facial features, etc due to the fetal position in the womb, are examples.