1. What is thick white tongue coating in babies? Thick white tongue coating in babies means that there is a white film on the surface of the baby\’s tongue. This condition is very common within a few days after birth, but if it persists and is accompanied by symptoms such as bad breath, parents need to pay attention. 2. What is the reason for the thick white coating on the baby\’s tongue? 1. Indigestion: If the baby has indigestion, food residues will remain in the mouth, and these residues will form a white coating on the tongue. 2.