Anencephaly

What is anencephaly?

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

Often, the brain lacks part or all of the cerebrum, the area of the brain that is responsible for thinking, vision, hearing, touch, and movement). There is no bony covering over the back of the head, and there may also be missing bones around the front and sides of the head.

What causes anencephaly?

Anencephaly is a type of neural tube defect. Neural tube defects, spina bifida (open spine), and anencephaly (open skull) are seen in about one of 10,000 pregnancies in the U.S. each year. The actual number is unknown because many of these births result in miscarriages. According to the Centers for Disease Control and Prevention (CDC), one in every 4,000 newborns in the United States has this condition.

During pregnancy, the brain and spine begin as a flat plate of cells, which rolls into a tube, called the neural tube. If all or part of the neural tube fails to close, leaving an opening, this is known as an open neural tube defect, or ONTD. This opening may be left exposed (80 percent of the time) or covered with bone or skin (20 percent of the time).

Anencephaly and spina bifida are the most common ONTDs.

What are the symptoms of anencephaly?

  • absence of bony covering over the back of the head
  • missing bones around the front and sides of the head
  • folding of the ears
  • cleft palate — a condition in which the roof of the child's mouth doesn't completely close, leaving an opening that can extend into the nasal cavity.
  • congenital heart defects

How is anencephaly diagnosed?

The diagnosis of anencephaly may be made during pregnancy or at birth by physical examination. Your baby's head might appear flattened due to the abnormal brain development and missing bones of the skull.

Diagnostic tests performed during pregnancy to evaluate your baby for anencephaly include:

  • alpha–fetoprotein: a protein produced by the fetus that is excreted into the amniotic fluid
  • amniocentesis: a test performed to determine chromosomal and genetic disorders and certain birth defects
  • ultrasound: a diagnostic imaging technique that uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs
  • blood tests

How is anencephaly treated?

Sadly, there is no medical treatment for anencephaly. Due to the lack of development of babies' brains, about 75 percent of infants are stillborn and the remaining 25 percent of babies die within a few hours, days, or weeks after delivery. Care focuses on providing emotional support to your family. Our social workers will offer you a network of support groups with families going through similar issues.

Also, we may recommend genetic counseling for parents to discuss the risk of recurrence in a future pregnancy as well as vitamin therapy (a prescription for folic acid) that can decrease the recurrence for ONTDs. Extra folic acid, a B vitamin, if taken one to two months prior to conception and throughout the first trimester of pregnancy, has been found to decrease the reoccurrence of ONTDs for couples who have had a previous child with an ONTD.

How we care for anencephaly

For expectant parents, finding out that there might be a problem, like anencephaly, with the health of your child understandably brings up questions, concerns, and fears. The Maternal Fetal Care Center of Boston Children's Hospital supports the needs of families and referring physicians at every step of care for a wide range of congenital anomalies, from diagnosis and counseling through treatment and follow-up care. MFCC's groundbreaking work has significantly improved outcomes for babies with complex health concerns, while delivering hope and compassionate care to families along the way.