May also be called: Microcephalus Microcephaly (my-kro-SEF-ah-lee) is a rare condition in which a child's brain does not fully develop, resulting in an abnormally small head size. More to Know Microcephaly, which can be passed down through families, can be present at birth or develop during the first 2 years of life. Chromosomal disorders (such as Down syndrome), metabolic disorders, bacterial meningitis, and lack of oxygen all can cause microcephaly. A baby is at increased risk if the mother used drugs or alcohol during her pregnancy or was exposed to chemicals, radiation, or certain viruses. Some children with microcephaly will have no symptoms or developmental delays, and will be generally unaffected. Others will have varying degrees of developmental problems depending on what caused the microcephaly. They may have intellectual disabilities, delayed speech and motor functions, vision and hearing problems, dwarfism or short stature, seizures, or other problems associated with brain abnormalities. Keep in Mind There is no treatment for microcephaly that can reverse the problem. Children who have it can, however, benefit from early intervention programs with physical, occupational, and speech therapists to help them reach their full potential and enhance their quality of life. All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts. Back to Articles Related Articles Fetal Alcohol Syndrome If a woman drinks alcohol during her pregnancy, her baby could be born with fetal alcohol syndrome (FAS), which causes a wide range of physical, behavioral, and learning problems. Read More Going to a Speech Therapist You might visit a speech therapist if you're having trouble speaking or understanding others. Find out more in this article for kids. Read More Delayed Speech or Language Development Knowing what's "normal" and what's not in speech and language development can help you figure out if you should be concerned or if your child is right on schedule. Read More Physical Therapy Physical therapy helps people get back to full strength and movement - and manage pain - in key parts of the body after an illness or injury. Read More Dwarfism Dwarfism is characterized by short stature. Many of the possible complications of dwarfism are treatable, and people of short stature lead healthy, active lives. Read More Going to a Physical Therapist Physical therapy uses exercises and other special treatments to help people move their bodies. Find out more in this article for kids. Read More Speech-Language Therapy Working with a certified speech-language pathologist can help a child with speech or language difficulties. Read More Seizures Seizures are caused by a sudden surge of electrical activity in the brain. Find out what you need to know about seizures and what to do if your child has one. Read More Down Syndrome Down syndrome is a condition in which extra genetic material causes delays in the way a child develops, both physically and mentally. Read More Support for Parents of Kids With Special Needs You might have more on your plate than most parents, but it doesn't mean you have to do it all alone. Here's how to ask for help and avoid caregiver burnout. Read More Birth Defects Some birth defects are minor and cause no problems; others cause major disabilities. Learn about the different types of birth defects, and how to help prevent them. Read More When Your Baby Has a Birth Defect If your child has a birth defect, you don't have to go it alone - many people and resources are available to help you. Read More Occupational Therapy Occupational therapy can help improve kids' cognitive, physical, and motor skills and build their self-esteem and sense of accomplishment. Read More Physical Therapy Doctors often recommend physical therapy for kids who have been injured or have movement problems from an illness, disease, or disability. Learn more about PT. Read More Down Syndrome What's up with Down syndrome? Find out in this article for kids. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.