Microcephaly

Microcephaly is a rare condition where your baby’s head is much smaller than expected for their size and age. It can happen because their brain didn’t develop properly during pregnancy. Or it doesn’t grow typically after birth.

To receive a microcephaly (my-crow-SEF-uh-lee) diagnosis, your baby’s head circumference must be in the 3rd percentile or lower. A head circumference in the 3rd percentile means 3% of all infants have a smaller head size, and 97% have a larger head size.

Microcephaly can happen alongside other birth defects. Or it may be the only condition your baby has. The brain is key to countless body and mind functions. Because of this, your baby may have difficulty with things like learning and movement.

But it’s impossible to predict what challenges microcephaly may bring. Your child’s healthcare team will guide you through the next steps.

Types of this condition

There are two types of microcephaly:

• Primary or congenital: Your baby is born with a small head.
• Secondary or acquired: The condition develops as your baby gets older.

Symptoms of microcephaly

A small head is the main symptom of microcephaly. The size of your baby’s brain affects the size of their head.

As your child grows older, their face continues to grow while their skull doesn’t. This may lead to a large face in comparison to their head size. They may also have a:

• Receding forehead
• Loose, wrinkled scalp
• Lower weight than expected for their age

Microcephaly causes

Microcephaly happens when there’s a lack of brain growth or changes to how your child’s brain grows. Healthcare providers can’t always find the exact cause. But it can be genetic or due to environmental factors.

Some causes of microcephaly include:

• Genetic or chromosomal syndromes, like Down syndrome
• Certain infections during pregnancy, like rubella, toxoplasmosis, cytomegalovirus (CMV) and Zika virus
• Exposure to toxins during pregnancy, like mercury, lead, radiation, alcohol or substances
• Unmanaged phenylketonuria (PKU) during pregnancy
• Severe malnutrition during pregnancy or after birth
• A lack of oxygen to the brain
• Brain injury or trauma during or after birth
• The skull bones fuse too soon (craniosynostosis)

Complications of this condition

Microcephaly can lead to complications, like:

• Delays in cognitive (thinking) development
• Delays in physical (movement) development
• Difficulty feeding or swallowing
• Hearing or vision loss
• Seizures

How doctors diagnose this condition

Healthcare providers can sometimes diagnose microcephaly before birth with a prenatal ultrasound. This happens late in the second trimester or in the third trimester.

But a diagnosis most often happens within 24 hours after birth. A provider will measure your baby’s head circumference (all the way around). Then, they’ll compare it to growth charts for their age. This also considers your baby’s length and weight.

If your baby has secondary microcephaly, a provider will diagnose the condition when it becomes noticeable.

Your child’s provider will likely suggest more tests to find the underlying cause. Tests may include:

• Imaging tests, like a head ultrasound or brain MRI
• Blood tests for genetic testing or to check for other underlying conditions

How is it treated?

There’s no treatment to make your baby’s brain and head grow. But certain therapies can help with issues related to microcephaly, like:

• Medications to treat seizures
• Services to help with learning milestones
• Speech, occupational and physical therapies to help with developmental milestones

Your child’s care team will likely include pediatricians, neurologists and therapists. They can provide treatment and education to help your baby’s health and well-being.

When should I see my child’s healthcare provider?

Visit your child’s healthcare provider if they:

• Miss developmental milestones for their age
• Don’t respond to their name or simple commands
• Have trouble eating or swallowing
• Don’t follow you or an object with their eyes

Call 911 or your local emergency services number if your child has a seizure.

It may be helpful to ask your child’s care team the following questions:

• Does my child have severe microcephaly?
• How will this condition affect my child’s development?
• Should I enroll my child in educational programs to help them learn?
• Are there side effects to the medications you prescribe?
• Are there signs of complications I should look out for?

What can I expect if my baby has this condition?

Microcephaly is a lifelong condition. Your child’s outlook depends on the cause and its severity.

Healthcare providers usually don’t know the effects of it until your child grows and develops. Their provider will monitor them to catch any complications that arise.

Life expectancy also varies. According to one study, about 80% of infants with severe microcephaly survived to 4 years of age. In general, children with just microcephaly are more likely to live longer than children with microcephaly and other conditions, like chromosomal syndromes.

But these are just statistics. Each case is unique.

Can this be prevented?

Microcephaly isn’t always preventable. You can’t control genetics. But you can reduce the risk of environmental causes by taking care of yourself during pregnancy. This could include:

• Eating a well-balanced diet
• Managing any underlying health conditions
• Avoiding toxic chemicals, alcohol and substances
• Going to checkups regularly to check the development of the fetus

Talk to your provider about other ways to stay healthy during pregnancy.