What are Anotia and Microtia?

Anotia and microtia are birth defects of a baby’s ear. Anotia happens when the external ear (the part of the ear that can be seen) is missing completely. Microtia happens when the external ear is small and not formed properly.

Anotia/microtia usually happens during the first few weeks of pregnancy. These defects can vary from being barely noticeable to being a major problem with how the ear formed. Most of the time, anotia/microtia affects how the baby’s ear looks, but usually the parts of the ear inside the head (the inner ear) are not affected. However, some babies with this defect also will have a narrow or missing ear canal.

Content provided by the Centers for Disease Control and Prevention (CDC). For information and references about anotia and microtia, please visit Facts about Anotia and Microtia | CDC ​.

Rates of Anotia and Microtia: 2018–2020​

Overall​

By Age

​By Race and Ethnicity

*Per 10,000 live births

**No cases in 2018–2​020

Data Source: California Birth Defects Monitoring Program Registry, 2018–2020, California 10-County Ca​​tchment Area (Fresno, Kern, Kings, Madera, Merced, Orange, San Diego, San Joaquin, Stanislaus, and Tulare)

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