Pregnancy produces quite the long list of changes in the female body. One of the changes is an increased need for water or hydration. When dehydrated, a white coated tongue can appear. Typically, white coated tongue is caused by a layer of bacteria or dead cells on the surface of the tongue. The condition is most often nothing to worry about and will go away with proper brushing and hydration. In some cases, however, a white coated tongue can be a sign of a bacterial infection.
The white coloring seen on the tongue is caused by an inflammation of the papillae. Papillae are small and look like miniature fingers. When these fingers swell, they take on a white appearance. In addition to dehydration using alcohol, smoking, breathing through the mouth and having a fever can cause a white coated tongue.