How does your baby get thrush?

There really isn't any good hard evidence for why babies get thrush, unless it was contracted from someone else that has thrush, or a side-effect of using an anti-biotic which kills the "good" bacteria that keep yeast from multiplying fast enough to cause an infection.

We all have yeast in our mouths and at some time for some reason they are able to grow very rapidly which inflames tissue and causes an infection. The best thing that you can do to prevent your baby from getting thrush or getting it again is to really sterilize bottles (in the dishwasher preferably) and keep your hands and all of their toys very clean.

I hope that helps :)

Thrush which resembles cottage cheese or milk curds on the sides, roof, and sometimes the tongue of a baby's mouth. It's most common in babies two months and younger, but it can appear in older babies, too. Everyone has yeast in their bodies, it's a normal part of the digestive system, but when there's an imbalance, an infection sets in. The main factors that can tip the balance are hormonal changes and the use of antibiotics, either in a breastfeeding mother or in a baby. Take care if your baby is placed on a course of antibiotics or if you're breastfeeding and take them to treat an infection. Antiobiotics kill off good, infection fighting bacteria as well as bad bacteria, either can trigger a case of thrush in the baby, especially if you contract a vaginal yeast infection in the process.