Neonatal candidiasis is a term doctors may use to refer to a yeast infection in a baby. Sometimes babies are born with a yeast infection and sometimes it can occur a few weeks after being born. There are two main forms it can take, either a skin yeast infection or an oral yeast infection (Thrush). When a woman has a vaginal yeast infection there is the chance of passing it to the baby as he or she passes through the birth canal. However both of these more common forms are easy to treat, and cause little distress usually for the baby.
There is something called invasive neonatal candidiasis however and that is very serious. It means the fungus has entered the blood stream of the baby, and since they have a very weak immune system that is not developed yet, this puts them at risk for organ infections and has a high mortality rate. Usually it is very premature and low birth weight babies that are more at risk for invasive neonatal candidiasis.