Microtia usually develops during the first trimester of pregnancy, in the early weeks of development. Its cause is mostly unknown but has sometimes been linked to drug or alcohol use during pregnancy, genetic conditions or changes, environmental triggers, and a diet low in carbohydrates and folic acid.

How common is microtia?

How common is microtia? Doctors diagnose microtia in roughly 1 to 5 out of 10,000 births. The condition occurs more often in boys than girls. It affects the right ear more often than the left.

Is microtia inherited?

In most cases, microtia is not genetically inherited. In 95% of children with microtia, there is no family history of microtia or other major ear anomalies in either the paternal or maternal side of the family.