November 9th is marked as Microtia Awareness Day. Microtia is a congenital birth defect in which the ear or ears do not fully develop during the 1st trimester of pregnancy. It means when one or both ears do not fully develop or are physically missing. Microtia is often accompanied by Aural Atresia – when the ear canals are underdeveloped or absent, resulting in hearing loss
In the United States, Microtia and Aural Atresia affect 1 in every 6,000 births which are approximately 663 babies born each year. There are an estimated 54,000 individuals currently living in the United States with Microtia and Atresia. Individuals born with Microtia face hearing loss, facial challenges, and the longing for social acceptance.
Some facts about microtia:
microtia: In this only one ear is affected. This is
the most common form as 90% of microtia cases are unilateral.
- Bilateral microtia: In this both the ears are affected. It occurs in one out of 25,000 births. In this case, children are at risk of greater hearing loss leading to poor speech development.
- Microtia occurs more often in males than in females and affects the right ear more than the left.
The Four Grades of Microtia
Grade 1: Your child may have a small ear with mostly normal ear anatomy, but the ear canal may be narrowed or missing. Though most normal features are present in this grade.
Grade 2: The bottom 1/3 of the ear of your child’s ear, including the earlobe, may appear to be normally developed, but the top two-thirds are small and malformed. The ear canal may be narrow or missing. A partial ear with a closed-off external ear canal producing hearing loss.
Grade 3: This is the most common type of microtia observed in infants and children. The ear appears as a small, peanut-shaped formation of cartilage and a relatively well-formed ear lobe. In grade 3 the external ear canal is usually absent.
Grade 4: Also referred to as anotia, it is the most severe form of microtia. Your child has anotia if there is no ear or ear canal present, either unilaterally or bilaterally.
What causes microtia?
Microtia is a congenital (present at birth) condition. No one exactly knows why microtia occurs, however environmental and drug factors have been questioned. It is said that Microtia usually develops during the first trimester of pregnancy, in the early weeks of development. Its cause is mostly unidentified 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.
One most recognizable risk factor for microtia is the use of acne medication Accutane (isotretinoin) during pregnancy. This medicine has been associated with multiple congenital abnormalities, including microtia.
Another possible reason can be diabetes, If the mother is diabetic before pregnancy it is of high risk for giving birth to a baby with microtia than other pregnant women.
Microtia doesn’t appear to be a genetically inherited condition, for the most part, if one or both parents have microtia, it is not necessarily passed on to their children.
How is microtia diagnosed?
The pediatrician should be able to diagnose your child’s microtia through observation. To determine the severity of microtia, your child’s doctor will order an exam with an ear, nose, and throat (ENT) specialist and hearing tests with a pediatric audiologist.
It’s also possible to diagnose the extent of a child’s microtia through a CAT scan, although this is mostly done only when a child is older.
The audiologist will examine the child’s level of hearing loss, and the ENT will confirm whether an ear canal is present or absent. Your child’s ENT will also be able to guide you regarding options for hearing assistance or reconstructive surgery.
Some families elect not to intervene surgically. If your child is an infant, reconstructive surgery of the ear canal can’t be done yet. If you’re uncomfortable with surgical options, you can wait until your child is older. Surgeries for microtia tend to be easier for older children, as there’s more cartilage available to graft.
It’s possible for some children born with microtia to use nonsurgical hearing devices. Depending on the extent of your child’s microtia, they may be a candidate for this type of device, especially if they’re too young for surgery or if you’re postponing it. Hearing aids may also be used if an ear canal is present.