Anencephaly is a condition present at birth that affects the formation of the brain and the skull bones that surround the head. Anencephaly results in only minimal development of the brain.

What is Anencephaly?

Anencephaly is a serious birth defect in which a fetus fails to develop parts of the brain, skull and scalp.

Affecting the central nervous system, the condition is considered a neural tube defect (NTD).  It occurs when the upper portion of the neural tube does not close properly, exposing areas of the brain and spinal cord to amniotic fluid and preventing the formation of tissue and bones. This typically happens by the fourth week of pregnancy.

Anencephaly affects an estimated 1 in 1,000 pregnancies in the United States. About 1 in every 5,000 to 10,000 babies is born with the condition.

How Does Anencephaly Affect my Baby?

Infants with anencephaly are born without large portions of the cerebrum and cerebellum, which control thinking, the senses, movement and balance respectively. In a majority of cases, the remaining brain tissue is not covered by skin or bone.

A number of pregnancies involving anencephaly end in miscarriage or stillbirth. Babies born alive with this congenital disorder may survive for several hours or days.

What Causes Anencephaly and Who is at Risk?

The causes of anencephaly are not fully understood, although there is some evidence of possible links to genetic and environmental factors. Risk factors may include:

  • Genes or chromosome changes
  • Insufficient intake of folic acid before and during early pregnancy
  • Exposure to environmental toxins
  • Certain medications and foods consumed during pregnancy
  • A previous pregnancy affected by anencephaly

How is Anencephaly Diagnosed?

Anencephaly may be diagnosed during pregnancy through a routine ultrasound or blood screening.  

Pregnancies involving anencephaly have abnormally high levels of a specific fetal protein (alpha-fetoprotein), detected in the mother’s blood or amniotic fluid. Additionally, imaging may reveal missing portions of the brain or skull, or abnormal facial features, on the developing fetus. 

If the condition is suspected, your physician may refer you to a fetal center for a comprehensive evaluation and or order additional testing, including:

  • Anatomy ultrasound: A high-resolution ultrasound to confirm the diagnosis and assess for other anomalies. 
  • MRI: A non-invasive imaging technique to help provide more detailed images of the brain and skull
  • Amniocentesis: A medical procedure in which a small sample of the amniotic fluid that surrounds the baby in the womb is extracted and studied in the lab and tested for genetic abnormalities. An amniocentesis can be used to confirm findings on the cell-free fetal DNA test. 
  • Cell-Free Fetal DNA testing: Your doctor can take a sample of your blood to look for copies of fetal (baby) DNA. This is only a screening test. A positive result means that there could be problems with the DNA. This should be confirmed with another test to be sure of the result.  

Sometimes anencephaly is diagnosed immediately following delivery, when the baby is born with brain or skull abnormalities.

Is Anencephaly Treatable or Curable?

There is no known treatment or cure for anencephaly. Infants affected by the condition rarely live longer than a few days.

Is Anencephaly Preventable?

While it may not be possible to prevent all cases of anencephaly, women can minimize their risk by ensuring proper intake of folic acid before and during pregnancy. This can be accomplished through diet or supplements. The Centers for Disease Control and Prevention (CDC) recommends a daily intake of 400 micrograms (mcg) of folic acid for all women of reproductive age. However, for women with prior affected babies, a daily intake of 4 mg of folic acid starting at least 1 month prior to a subsequent pregnancy is recommended.   

Perinatal Palliative Care

When prenatal testing shows that a baby has a life-threatening or life-limiting condition, many parents feel overwhelmed with the challenges of expecting a newborn with a complex illness.

Perinatal palliative care is designed to help families through an often confusing and heartbreaking diagnosis, and to help them cope with the challenges of expecting a newborn with a fatal illness.

You will be faced with many difficult decisions following your baby’s diagnosis. The goal of Perinatal Palliative Care is to provide compassionate and expert care starting from the time of diagnosis. While there may not be curative treatments for many of the conditions commonly referred for palliative care, there are many things the team can do to help support you, your baby, and your family.

Who is Part of a Perinatal Palliative Care Team?

Perinatal palliative care is provided by a multi-disciplinary team of specialists. The team is committed to supporting you and your family. You and your family will meet with members of the palliative care team before delivery, and have additional visits as needed during your pregnancy and after delivery.

Palliative care is highly individual and there is no one right path for every family. We will help guide you through making decisions about how to best care for your baby, decisions that fit with your goals and values. 

Many families find the time between diagnosis and delivery very emotionally difficult. Coordinators can help connect you with counseling services and support groups.