Thrush is a yeast infection that occurs most often in the mouths of infants 2 months old and younger. Thrush may be accompanied by a diaper rash, also associated with yeast. In some babies, thrush can cause difficulty feeding due to soreness and sensitivity caused by the infection. An imbalance of yeast versus healthy bacteria in an infant causes thrush, and can be attributed to three factors.
Antibiotics During Labor
Women often receive antibiotics during labor as treatment for group B strep bacteria which can cause serious infections if passed on to the newborn baby. Other women receive antibiotics to prevent infections from prolonged rupture of membranes, meaning that membranes ruptured and water broke without delivery resulting within 24 hours. For C-section mothers, antibiotics are often given to prevent infection after surgery. Antibiotics are often nonspecific to harmful bacteria, killing beneficial bacteria as well. According to Dr. William Sears, when good bacteria are not present to control the growth of yeast, it grows out of control causing yeast infections. Yeast is then passed from the mother to the baby during delivery or breastfeeding.
Antibiotics Administered To Infant
After birth, antibiotics may be administered to infants who develop fevers. These antibiotics work in the same way as those given to mom, killing both harmful and beneficial bacteria. Babies who have received antibiotics easily develop thrush due to an already weakened immune system. While nursing, it is possible for thrush to be passed from the baby to the mother. If untreated in both, it can be passed back and forth continuously. Treatment involves the administration of Nystatin, an anti-fungal liquid, which is applied directly to the mouth and nipples if the mother is breastfeeding.
Other causes
In some instances, thrush occurs in a newborn when no antibiotics were given. According to the University of Michigan Health System, some newborns acquire thrush simply due to an immature immune system. Dr. Sears points out that sometimes there are simply no known reasons for some cases of thrush. Some newborns are more susceptible to thrush than other babies, with no correlation providing an identifiable cause.
