Microtia and anotia

What are microtia and anotia?

Microtia and anotia are birth defects of a baby’s ear. Birth defects are structural changes present at birth that can affect almost any part of the body. They may affect how the body looks, works or both. Birth defects can cause problems in overall health, how the body develops or how the body works.

Anotia is a form of microtia. Microtia can vary from being barely noticeable to being a serious health problem.

About 1 to 5 in 10,000 babies is born with microtia or anotia in the United States each year.

What are the different types of microtia?

Microtia happens when the outer ear is smaller than normal and doesn’t form correctly. Microtia can range in how severe it is, from being a partially formed ear to being a lump of tissue where the ear should be. Sometimes the ear canal is very narrow or missing completely. The ear canal is the pathway that leads from the outside of the ear to the middle ear.

Microtia can affect one or both ears:

• Unilateral microtia is when one ear is affected. This is the most common form. About 9 in 10 (90 percent) microtia cases are unilateral. It appears on the right side of the head twice as often as the left side.
• Bilateral microtia is when both ears are affected. It happens in about 1 in 25,000 babies.

There are four types of microtia:

1. Type I microtia. The ear is slightly smaller than usual, but all other parts of the ear are healthy. This is the mildest form of microtia.
2. Type II microtia (also called conchal type microtia). This is when a baby has a partial ear with a narrow or closed ear canal. A baby with Type II microtia has some hearing loss. Hearing loss is being partly or totally unable to hear sound in one or both ears. It can happen when any part of the ear isn’t working in the usual way. Hearing loss can affect a baby’s ability to develop speech, language and social skills.
3. Type III microtia (also called lobular type microtia). This is the most common type of microtia. The ear looks like a small peanut with an ear lobe. The ear canal and ear drum are usually missing (called aural atresia). Most babies with Type III microtia have hearing loss.
4. Type IV microtia (also called anotia). This is the most severe and rarest type. Anotia happens when both the inside and outside parts of the ear are missing. It can affect one or both ears, but it’s more common for babies to have anotia in only one ear. Babies with anotia have conductive hearing loss. This happens when there’s a problem in the outer or middle ear that slows or prevents sound waves from passing through.

How is microtia diagnosed?

If your baby has microtia, your baby’s health care provider sees the condition when she gives your baby a physical exam after birth. In rare cases, your provider may see that your baby has microtia before birth on a routine ultrasound or MRI. Ultrasound is a prenatal test that uses sound waves and a computer screen to show a picture of your baby inside the womb. An MRI uses a large magnet and radio waves to make a detailed picture of the inside of your body.

If your baby has microtia, his provider also checks him for other birth defects. For example, your baby may get an ultrasound to check for birth defects of the kidneys. This is because the urinary tract forms at the same time as the ear while your baby is in the womb. The urinary tract is the system of organs (like the kidneys and bladder) that helps your body get rid of waste and extra fluids.

What health care providers treat microtia?

Depending on your baby’s health problems, his medical team may include a variety of health care providers:

Doctors, like:

• A pediatrician takes care of babies and children
• A pediatric surgeon has special training doing surgery on babies and children
• A neonatologist is a pediatrician who has special medical training to take care of sick newborns, including premature babies (born before 37 weeks of pregnancy) and babies with birth defects
• An otolaryngologist (also called an ENT) is a doctor who treats problems of the ears, nose and throat
• A pediatric plastic surgeon is a doctor who repairs or rebuilds parts of a baby or child’s body to improve how they work and look

Other kinds of providers, like:

• An audiologist is someone with special training to diagnose and treat hearing loss in newborns, children and adults
• A genetic counselor is trained to help you understand about genes, birth defects and other medical conditions that run in families, and how they can affect your health and your baby's health
• A social worker is a mental health professional who helps people solve problems and make their lives better. Most hospitals have social workers who can help connect you with the resources you need to care for your baby.
• A speech pathologist is a professional who can help your child speak more clearly or communicate in other ways

How is microtia treated?

Your baby’s treatment depends on the type of microtia he has and how severe it is. Some babies may need several surgeries, while others don’t need any treatment. After birth, your baby’s provider or an audiologist tests his hearing. If your baby has a hearing problem, his provider may recommend hearing aids to improve his hearing and help him learn to speak. Hearing aids make sounds louder. They can help babies as young as 1 month old.

Most children with microtia have ear reconstruction surgery to rebuild the ear, but they have this surgery later in life. The age when your child has surgery depends on how severe his condition is, but reconstruction surgery is usually done in stages when a child is between 3 and 10 years old. Reconstructed ears last for your child’s entire life. Children with microtia can play contact sports and enjoy other activities without any extra protection.

Children with microtia may these surgeries:

• MEDPOR® implant surgery. This surgery may involve one or two surgeries and your child may have surgery as young as three years old. Your child’s pediatric plastic surgeon uses a manmade framework (also called an implant) and your child’s body tissue to create an ear. If your child only needs one new ear, the framework is made to match the healthy ear. It’s made a bit larger for young children so that it’s close to adult size. This way it fits your child as he grows. The surgeon covers the implant with a large, thin membrane called the fascia flap that’s above your child’s ear in the temple area. The surgeon also may use skin from other parts of your child’s head to cover the flap so the skin color better matches your child’s other ear.
• Autologous ear reconstruction using rib cartilage. This surgery involves several stages of surgery to make the new ear and position it correctly on your child’s head. It’s usually done when a child is older because the surgeon needs to remove cartilage from a rib in your child’s chest and use it to make the new ear. If a child is too young, there may not be enough cartilage to work with. Cartilage is a tough, flexible body tissue that is made mostly of water. It can be found throughout the body, including between the bones (like the ribs) and joints and in the nose and ear. Your child’s surgeon also may want to wait until your child’s other ear has grown to its adult size before doing this surgery.

The surgeon uses the cartilage to create a frame to build the rest of the ear. This surgery uses your baby’s own tissue so if the new ear is ever injured, it heals just like a natural ear. The rebuilt ear may not look exactly like your baby’s other ear but it helps even out his appearance and allows him to wear glasses if needed.

If your baby has bilateral microtia, his surgeon repairs the outer ears before opening the ear canals (if needed). Surgery to treat anotia is like surgery for other types of microtia. The main difference is that if your baby’s ear is completely missing, he also needs to have an earlobe made by a plastic surgeon. The surgeon can use your baby’s rib cartilage to make the earlobe.

Other treatments for microtia may include:

• An ear prosthesis (also called artificial ear). These are manmade ears that are more commonly used in adults who develop hearing loss. They’re not usually a good choice for young children because they’re costly, fragile and need regular upkeep in order to work well.
• Speech-language therapy. Your baby’s provider checks your baby for language and developmental delays as he grows and may suggest therapy. Speech-language therapy is the treatment for kids with speech or language disorders. A speech disorder is happens when a child has a problem making sounds. A language disorder is when a child has a problem understanding or putting words together to communicate ideas.

How can microtia or anotia affect your baby’s health and development?

Most babies born with microtia are healthy, but some babies with microtia or anotia have:

• Hearing loss. Hearing loss even in just one ear may affect how your baby learns to talk. It also may make it hard to learn in school.
• Ear infections. If your baby has a narrow ear canal, ear wax may build up. This can cause an infection in the outer part of the ear. Your baby may need a small tube placed in his ear to relieve pressure and help air flow in his ear to prevent infections.
• Self-esteem issues. Some children with anotia or microtia may have issues with self-esteem because they may look different than other children. Support groups may be helpful for you and your child.
• Nerve issues in the face. Up to 3 in 20 (15 percent) babies born with microtia have some nerve weakness in the face.
• Other issues. Related issues, such as cleft lip or palate or issues with the heart or urinary system, are rare. Cleft lip is a birth defect in which a baby’s upper lip doesn’t form completely and has an opening in it. Cleft palate is a birth defect in which a baby’s palate (roof of the mouth) doesn’t form completely and has an opening in it.

What causes microtia?

We don’t know the exact cause of microtia, but it may be caused by a drop in blood supply or oxygen levels to your baby in the womb. There are some things that may make you more likely than other women to have a baby with microtia. These are called risk factors. Having a risk factor doesn’t mean for sure that your baby will be affected. But it may increase your chances. If you’re pregnant or thinking about getting pregnant, talk with your provider about things you can do to help reduce your risk for having a baby with microtia.

Risk factors for microtia may include:

Being Hispanic or American Indian/Alaskan Native. If you or your partner is Hispanic or American Indian/Alaskan Native, you may be more likely to have a baby with these birth defects than other people. We don’t know why race and ethnicity may play a role in these birth defects. More research is needed to better understand them.

Changes in genes (also called mutations). Genes are parts of your body’s cells that store instructions for the way your body grows and works. Genes are passed from parents to children. Certain gene mutations are linked to birth defects. In most cases, there is no family history of microtia. Your family history is a record of any health conditions and treatments that you, your partner and everyone in your families have had. If you do have a family history of microtia, you may want to talk to a genetic counselor to learn about your chances of having a baby with this condition.

Taking certain medicines before and during pregnancy. Talk to your provider about any prescription medicines or over-the-counter medicines, supplements and herbal products you take. Taking some medicines just before you get pregnant or during pregnancy may increase your risk of having a baby with microtia. These medicines include isotretinoin (Accutane®), Thalidomide (Thalomid®) and mycophenolate mofetil (CellCept®). Isotretinoin is a prescription medicine used to treat a severe type of acne. Thalidomide is used to treat certain skin conditions, infections, certain types of cancer and complications from HIV (human immunodeficiency virus). Mycophenolate mofetil is a medicine used in organ transplant patients to help prevent organ rejection. You may need to stop taking a medicine or switch to one that’s safer during pregnancy. Don’t start or stop taking any medicine without talking to your provider first. Stopping some medicines suddenly may cause severe problems for you or your baby. Your provider can help you stop using them in a safe way.

Having preexisting diabetes. Women who have diabetes before they get pregnant have a higher risk of having a baby with microtia. Diabetes is a medical condition in which your body has too much sugar (called glucose or blood sugar) in your blood. This can damage organs in your body, including blood vessels, nerves, eyes and kidneys. If you have preexisting diabetes, work to get it under control 3 to 6 months before pregnancy. Monitor your blood sugar, take your diabetes medicine, eat healthy foods and be active every day.

Drinking alcohol or using street drugs (like methamphetamine) during pregnancy. Fetal alcohol syndrome (also called FAS) may cause microtia. FAS is a kind of fetal alcohol syndrome disorder (also called FASDs). FASDs are a group of conditions that can happen in a baby whose mother drank alcohol during pregnancy. Children with FAS may have abnormal facial features, growth problems and problems with the central nervous system (also called CNS). The CNS is made of up of the brain, spinal cord and nerves. It helps you move, think and feel. FAS can cause learning, memory, communication, vision or hearing problems. People with FAS may have a combination of these problems, have a hard time in school and have trouble getting along with others. Methamphetamine (also called meth, blue, ice and crystal) is a powerful street drug that affects the CNS.

More research is needed, but doing these things during pregnancy may increase your risk of having a baby with microtia. Tell your health care provider if you need help to quit drinking or using drugs. If you stop taking alcohol or drugs suddenly on your own, it may cause severe problems for you and your baby. Your provider can help you quit safely.

Eating foods low in folic acid and carbohydrates. Folic acid is a vitamin that every cell in your body needs for healthy growth and development. If you take it before pregnancy and during early pregnancy, it can help protect your baby from birth defects.

It’s hard to get all the folic acid you need from food. Even if you eat foods that have folic acid in them, take your vitamin supplement every day:

• Before pregnancy, take a vitamin supplement that has 400 micrograms of folic acid in it every day.
• During pregnancy, take a prenatal vitamin that has 600 micrograms of folic acid in it every day. Eat healthy foods with folic acid or folate.

Look for the word “fortified” or “enriched” on labels of foods. This means folic acid has been added to the food. Check the labels for foods including:

• Bread
• Breakfast cereals
• Flour
• Pasta
• Products made from a kind of flour called corn masa, like tortillas, tortilla chips, taco shells, tamales and pupusas
• White rice

Some fruits and vegetables are good sources of folic acid, too. When folic acid is naturally in a food, it’s called folate. Foods that are good sources of folate include:

• Beans (like lentils or black beans)
• Leafy green vegetables (like spinach and Romaine lettuce)
• Broccoli
• Citrus fruits (like oranges and grapefruits) 

Carbohydrates are one of the key nutrients in foods. They help give the body energy. Foods that are good sources of carbohydrates include:

• Breads, cereals and tortillas
• Whole grains, like brown rice, oats, barely and quinoa
• Vegetables, like broccoli potatoes, green peas and corn
• Fruits, like raspberries, pears and apples

If you have a health condition like diabetes, you may need to count how many carbohydrates you eat. Work with your health care providers and others, like a diabetes educator or registered dietician (also called RD), to make sure your get the right amount of carbohydrates. A diabetes educator has training to help you control your blood sugar. An RD is a health professional with training to help you use diet and nutrition to help you stay healthy.

Are some babies at increased risk of having microtia?

Your baby may be at increased risk of having microtia if he’s a boy or has other birth defects. Microtia affects twice as many boys than girls. Microtia can happen as part of a group of birth defects that include:

• Hemifacial microsomia, when part of the face is smaller than normal
• Goldenhar syndrome, when the lower half of one side of the face doesn’t grow normally and non-cancer growths develop in the eye
• Treacher Collins syndrome, a condition that affects the development of bones and other tissues of the face

More information

• Centers for Disease Control and Prevention (CDC)
• Children’s Craniofacial Association
• The National Craniofacial Association (FACES)

Last reviewed: July, 2019