Anencephaly: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Anencephaly?
An obstetrician (a doctor who cares for women during pregnancy) leads care. A neonatologist (a doctor for newborns) or a pediatrician (a children's doctor) cares for the baby after birth. A genetic counselor (a helper for family planning questions) can talk about future pregnancies. 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 anencephaly?
Anencephaly is a serious birth defect. A baby with anencephaly is born without parts of the brain and skull. It is fatal and there is no cure or treatment. The news is very hard for families. Care teams can help you know what to expect.
Anencephaly is a type of neural tube defect. The neural tube is the structure in an unborn baby that becomes the brain and spinal cord. In anencephaly, the upper part of the neural tube does not close all the way. This happens in the first few weeks of the baby's growth.
At birth, the baby often has no front part of the brain (forebrain). The thinking and coordinating part of the brain (cerebrum) is also missing. There may be no bone or skin over the rest of the brain. These brain parts are needed for thinking, hearing, vision, emotion, and coordinating movement.
Almost all babies with anencephaly die before birth or within a few hours or days after birth.
Symptoms
Anencephaly can be found during pregnancy or at birth. Health care providers can see it right away at birth. Signs at birth include:
- Absence of the skull.
- Absence of parts of the brain.
- Facial features that look different from usual.
- Severe developmental delay (the baby does not grow as expected).
Heart defects may be present in 1 out of 5 cases.
Causes and who gets it
The exact cause of anencephaly is not known. It likely comes from a mix of genetic and environmental factors. Anencephaly is one of the most common types of neural tube defect. In the United States, about 1 in every 4,762 babies is born with anencephaly.
Some factors in pregnancy might raise the chance of anencephaly:
- Low folate (vitamin B9) levels in early pregnancy.
- Health conditions, such as diabetes, that are not well controlled.
- Certain medicines, such as antiseizure medicines.
- Overheating (like getting in a hot tub) or fever.
- Obesity.
Most cases are sporadic. This means they happen in families with no history of the condition. Having one baby with anencephaly raises the risk of another child with a neural tube defect.
How doctors diagnose it
Health care providers may find anencephaly during pregnancy or after birth. An ultrasound is done to confirm the diagnosis. An ultrasound is a scan that uses sound waves to make pictures of the baby. A blood test in pregnancy can also show an abnormal result.
Other tests may include:
- Amniocentesis (a test that takes a little fluid from around the baby). It looks for increased levels of alpha-fetoprotein.
- Alpha-fetoprotein blood level. Alpha-fetoprotein is a protein made by the growing baby. Increased levels suggest a neural tube defect.
- Urine estriol level (a urine test for a hormone made in pregnancy).
The ultrasound may also show too much fluid in the uterus (womb). This is called polyhydramnios.
Treatment
There is no current treatment for anencephaly. There is no known cure or standard treatment. Talk to your health care provider about care decisions. If anencephaly is found before birth, further counseling will be needed. Counselors and your care team can help your family plan next steps.
When to see a doctor
A provider usually finds anencephaly during routine prenatal testing and ultrasound. Otherwise, it is seen at birth. If a blood test or ultrasound in pregnancy shows any sign of anencephaly, contact your doctor right away. If anencephaly is found before birth, further counseling will be needed to help your family know what to expect.
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. This doctor can review test results with you and explain them in plain words. The doctor can also refer you to specialists and counselors and see you for follow-up visits.
Common questions
Is there any treatment for anencephaly?
No. It is fatal and there is no cure or treatment. Talk to your health care provider about care decisions. If it is found before birth, further counseling will be needed.
What causes anencephaly?
The exact cause is not known. It likely comes from a mix of genetic and environmental factors. Low folate (vitamin B9) levels in early pregnancy might raise the chance. Researchers do not know all the causes yet.
Can anencephaly be prevented?
Not completely, but taking folic acid before and during pregnancy can lower the risk of some birth defects, including anencephaly. Women who are pregnant or planning a pregnancy should take a multivitamin with folic acid every day. Many foods now have folic acid added. Getting enough folic acid can cut the chances of neural tube defects in half.
Could anencephaly happen again in another pregnancy?
Having one baby with anencephaly raises the risk of another child with a neural tube defect. Further counseling will be needed to talk about the risk with you. Taking folic acid before pregnancy can help lower the risk.
Sources
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.
