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Medically reviewed by Last updated on Oct 1, 2023.

What do I need to know about microcephaly?

When your baby's head is smaller than expected, it is called microcephaly. As your baby develops, his or her head grows as the brain grows. Microcephaly can be diagnosed before or after your baby is born. Severe microcephaly can happen if your baby's brain does not grow at all. It can also happen if your baby's brain starts to grow and an injury happens before or after birth. Severe microcephaly is life-threatening.

What causes microcephaly?

The cause of microcephaly may not be known. Microcephaly is often associated with Down syndrome, chromosomal syndromes, and neurometabolic syndromes.

  • The following may have affected your baby:
    • Blood supply to the brain was stopped while it was developing
    • Abnormal genes
  • The following may have affected your baby's mother while she was pregnant:
    • Infections such as Zika virus, rubella, cytomegalovirus, toxoplasmosis
    • Not enough food or certain nutrients
    • Alcohol, certain drugs, toxic chemicals

What signs and symptoms may happen with microcephaly?

Your baby may have any of the following mild to severe symptoms:

  • Seizures
  • Problems with speech
  • Problems with movement and balance when he or she sits up, stands, or walks
  • Trouble swallowing
  • Not being able to learn or function with daily activities
  • Hearing loss and vision problems

How is microcephaly diagnosed?

  • Before your baby is born: An ultrasound may show your baby has microcephaly while you are pregnant.
    Pregnancy Ultrasound
  • After your baby is born: Your baby's head is measured and compared to other children who are the same age and sex. An MRI will show how your baby's brain has developed. It may also show if your baby had an infection before birth. Your baby may be given contrast liquid to help the pictures show up better. Tell a healthcare provider if you or your baby have ever had an allergic reaction to contrast liquid. Do not enter the MRI room with anything metal. Metal can cause serious injury. Tell a healthcare provider if you have any metal in or on your body.

How is microcephaly treated?

Your baby may not need any treatment with mild microcephaly. Other medical problems caused by microcephaly may need to be treated. Your baby may also need speech, physical, or occupational therapy. These therapies will help your child function at his or her highest level as he or she grows. Life-long treatment will be needed for babies with severe microcephaly. Severe microcephaly may be life-threatening.

When should I call my baby's doctor?

  • You have questions or concerns about your baby's development, condition, or care.

Care Agreement

You have the right to help plan your baby's care. Learn about your baby's health condition and how it may be treated. Discuss treatment options with your baby's healthcare providers to decide what care you want for your baby. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

© Copyright Merative 2023 Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.