What is microtia?
A child with microtia has an ear(s) that isn’t fully developed; microtia affects how the outer ear looks. This condition develops before babies are born, during the first four months of a mother’s pregnancy.
Ears affected with microtia can be:
- Slightly smaller than normal
- Significantly smaller than normal with differences in parts of the ear
- Absent (anotia)
What is atresia of the ear canal?
A child with atresia is born without an external ear canal. Atresia can be complete where there is no ear opening or there can be a very thin opening of the external ear canal. The level of hearing loss that atresia creates varies depending on the opening.
What is microtia-atresia?
Children with microtia-atresia have both a small or absent outer ear and they are missing an ear canal.
A child with microtia-atresia may have additional health challenges, including syndromes that affect the face like hemifacial microsomia or Oculo-Auriculo-Vertebral (Goldenhar) syndrome.
When an individual has microtia or microtia-atresia and no other developmental conditions, it’s called isolated microtia.
Where did the name microtia-atresia come from?
The name can be broken down into “micro,” which means small; “otia,” which means ear; and “atresia,” which means without an opening.
What causes microtia and atresia?
Microtia happens because of a mix of genetic and environmental factors. The exact cause for most patients is not clear. Sometimes, the condition is passed to a child from a parent.
The prescription drugs Isotretinoin (Accutane) and Thalidomide can cause microtia (and other conditions) when used during early pregnancy. Both drugs are not allowed to be used in women who are pregnant.
“Mothers sometimes worry that actions they took during pregnancy caused microtia and atresia. However, except in very rare cases where the mother may have used medications known to cause microtia and birth defects, having a baby with microtia and/or atresia is not the mother’s fault. She did not eat too much or too little or dance too much or too little. She also did not allow the baby to lie in one position too long.”
- Peggy Kelley, MD
Who gets microtia and atresia?
Babies of any ethnicity can get microtia-atresia. However, it’s more common in Hispanic and Native American ethnic groups.
Rate of occurrence by ethnicity:
Navajo, Inuit, Andean: 1 in 1,200 live births
Native Americans: 1 in 1,800 live births
Hispanic: 1 in 10,000 live births
Asian: 1 in 10,000 live births
Caucasian: 1 in 20,000 live births
African: 1 in 40,000 live births
What are the signs and symptoms of microtia and atresia?
Microtia can be diagnosed and seen on a 20-week ultrasound. However, it is not routinely evaluated during a normal pregnancy.
Once a baby is born, parents and health care specialists will notice:
- Unusual ear size
- Unusual shape of the outer ear
- A closed or very small ear canal opening
What is the risk of future children having microtia-atresia?
The risk of having a child with microtia-atresia is low. The risk of having more than one child with microtia-atresia is also low unless your ethnicity has a high rate of occurrence, like Native American. However, it is still rare to have parents and children or siblings with microtia-atresia.
What tests are used to diagnose microtia-atresia?
All newborns with microtia-atresia should receive a diagnostic Auditory Evoked Potentials (AEP) (or auditory brainstem response/ABR) evaluation within three months of birth. The test can be done as early as any routine newborn hearing screening.
An AEP/ABR evaluation is completed by a Doctor of Audiology (Au.D.). It is highly recommended that newborns diagnosed with hearing loss find a pediatric audiologist for care. Learn about the Audiology, Speech and Learning Center at Children’s Colorado.
Testing for older children
All children should receive a hearing screening when starting public school and then be referred for a diagnostic hearing test. However, hearing loss can be missed in newborns if screening isn’t done prior to hospital discharge after birth, and/or if follow-up for young children is not recommended by the pediatrician or birth hospital. This can happen if microtia/atresia is only in one ear because hearing loss in one ear is harder to detect.
How do specialists at Children’s Hospital Colorado make a diagnosis?
In order to diagnose microtia-atresia, your child should see a microtia specialist. When you visit Children’s Colorado's Microtia Clinic, a specialist completes an evaluation of the child’s ear.
During the evaluation, the specialist:
- Evaluates the outer ear and ear canal (if there is one)
- Tests hearing in both ears, even if the canals are not closed
An otolaryngologist (Ear, Nose and Throat specialist) or a plastic surgeon and an audiologist, who are knowledgeable about microtia, complete the evaluation and provide a diagnosis. Sometimes, the child sees other specialists, such as a speech therapist for a language delay.
The Microtia Clinic at Children’s Hospital Colorado
Colorado Families for Hands & Voices
Parent-run organization that supports families with children who are deaf or hard of hearing without a bias around communication modes or methodology.
Colorado Hearing Resource Coordinator
Assists families with children birth to 3 -years -old in obtaining access to funding, community resources, coordination of services and providing expertise about hearing loss.
Colorado School for the Deaf and Blind
Hard of hearing and deaf adult role models who are trained to provide awareness experiences to increase understanding of the needs of a student who is hard of hearing / deaf and to improve this child’s sense of identity and self-esteem.
Online support group for individuals with Microtia and Atresia.
Phonak Guide to Access Planning
Provides information that is important to effectively and independently advocate and be responsible for your communication access supports.