Microcephaly: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Microcephaly?
A pediatrician, a doctor for children, usually notices microcephaly at baby check-ups. A pediatric neurologist, a doctor who treats the brain and nerves in children, often helps manage it. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is microcephaly?
Microcephaly is a condition where a baby's head is much smaller than expected. It is a birth defect.
During pregnancy, a baby's head grows because the baby's brain grows. It can happen when the brain did not develop properly in pregnancy or stopped growing after birth. It can occur alone or together with other major birth defects.
Head size is measured as the distance around the top of the head. Doctors compare it with standard growth charts. About 1 in every 1,150 babies in the United States has microcephaly.
Symptoms
The main sign is a head much smaller than others of the same age and sex. Babies with mild microcephaly often do not experience any additional problems.
Babies can have several health problems, depending on how severe it is. Common problems include:
- Seizures.
- Developmental delay, such as problems with speech and walking.
- Intellectual disability.
- Problems with movement and balance.
- Feeding problems, such as trouble swallowing.
- Hearing loss.
- Vision problems.
Severe microcephaly is a serious, extreme form of the condition. It can be life-threatening.
Causes and who gets it
Most often, the brain does not grow at a normal rate. Infections, genetic disorders, and severe malnutrition can affect brain growth. The cause is unknown in most babies.
Known causes include:
- Infections during pregnancy, such as Zika, toxoplasmosis, or CMV (cytomegalovirus). Congenital rubella, an infection present at birth, can also cause it.
- Poor nutrition (malnutrition) during pregnancy, or in the baby after birth.
- Exposure to harmful substances, such as alcohol or certain drugs.
- Problems with blood supply to the baby's brain.
- Uncontrolled phenylketonuria (PKU) in the mother, or methylmercury poisoning.
Some genetic conditions can also cause microcephaly. Examples are Down syndrome, Cri du chat syndrome, Cornelia de Lange syndrome, and trisomy 18.
How doctors diagnose it
Doctors can diagnose microcephaly during pregnancy with ultrasound, or after the baby is born. Prenatal diagnosis can be done late in the second or early in the third trimester.
After birth, a provider measures around the baby's head. The provider compares it with charts based on age and sex. Head measurements are part of all well-baby exams for the first 18 months.
The provider keeps records over time to see if the head grows slower than the body. If it is suspected, tests can help confirm it and look for other problems. For example, magnetic resonance imaging (MRI) can show the structure of the baby's brain.
Treatment
It is a lifelong condition. There is no known cure or standard treatment. It can range from mild to severe, and treatment ranges as well.
Babies with mild microcephaly need regular check-ups to track growth and development. More severe cases need ongoing care for their health problems.
Early services often help babies build their physical and thinking skills. These services are called early intervention. They can include speech, occupational, and physical therapy. Sometimes medicines are also needed to treat seizures or other symptoms.
When to see a doctor
Talk to your child's provider if the head looks too small or is not growing normally. Most often, microcephaly is diagnosed at birth or during routine well-baby exams.
Tell your provider if you or your partner has been to an area with Zika and you are pregnant or planning to be.
Call 911 or go to the emergency room if your child has bluish or grey skin, trouble breathing, or loses consciousness. Also call 911 if a seizure lasts more than 2 to 5 minutes.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. A direct primary care or concierge doctor can measure your baby's head at routine well-baby visits. They can also do the regular check-ups that track growth and development.
Common questions
Can microcephaly be cured?
No, there is no known cure or standard treatment. Early help, such as speech, occupational, and physical therapy, often improves a baby's abilities.
What causes microcephaly?
The cause is unknown in most babies. Known causes include infections in pregnancy, such as Zika. Others are malnutrition, alcohol or certain drugs, and poor blood supply to the brain.
Can doctors find microcephaly before a baby is born?
Yes, it can be diagnosed during pregnancy through ultrasound. This can be done late in the second or early in the third trimester.
Do all babies with microcephaly have other health problems?
No, babies with a mild form often have no other problems. They still need regular check-ups.
How is microcephaly diagnosed after birth?
Microcephaly is diagnosed after birth by measuring the distance around the baby's head and comparing it with charts for age and sex. Tests such as MRI can help confirm it.
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Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
