What is it?

Micrognathia is a condition where the mandible (jaw bone) is very small.

How common is it?

Micrognathia occurs in approximately 1 in 1600 pregnancies.

How is it managed?

If suspected, a detailed ultrasound will be performed to look for other abnormalities. Additional imaging, such as 3D ultrasound and MRI, can allow for better visualization of the jaw. Genetic counseling and testing via amniocentesis will be recommended to evaluate for genetic causes of micrognathia. There are no treatments recommended prior to delivery. Prenatal care will be managed by a Maternal-Fetal Medicine specialist, an obstetrician with special training and expertise in high-risk pregnancies. Consultations with neonatology and specialty surgeons are recommended to discuss prognosis and management options after birth.


Newborns with micrognathia are at risk for having breathing difficulty after birth, and therefore require a carefully coordinated delivery. Monitoring of breathing and feeding is important during the first days of life. In some cases, surgery may be necessary after birth. The outcome for infants born with micrognathia will depend on whether other abnormalities are present.