Anencephaly: Definition, Symptoms, Diagnosis, Causes, Treatment and Tips

It is a type of birth defect in which the crucial parts of the baby’s brain and skull do not form.

Unfortunately, babies affected by anencephaly are often stillborn or die at birth.

Even if they are born alive, babies with anencephaly always die within a few days of being born. There is no treatment that can change the prognosis.

Understanding neural tube defects

Anencephaly is a type of neural tube defect (NTD), which are birth defects that affect the brain, spine, or spinal cord . These are conditions where the developing neural tube does not close properly during the baby’s development very early in the first trimester.

Neural tube defects have a wide range of severity, from minor health problems to 100% mortality.

In the severe range of that spectrum is anencephaly, one of the most devastating diagnoses expectant parents can receive during pregnancy. Unfortunately, babies with anencephaly can never gain consciousness or carry out the physical functions of life because important parts of their brain are missing.

Because the skull is also affected by the disorder, babies with anencephaly are often physically deformed and parts of the brain may be exposed.

Symptoms and diagnosis

The diagnosis of anencephaly can be made during pregnancy or at birth through a physical exam. The baby’s head often appears crushed due to abnormal brain development and lack of skull bones.

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

  • Alpha-fetoprotein: a protein produced by the fetus that is excreted in the amniotic fluid. Abnormal alpha-fetoprotein levels can indicate brain or spinal cord defects, multiple fetuses, a miscalculated due date, or chromosomal disorders.
  • Amniocentesis: a test done to determine chromosomal and genetic disorders and certain birth defects. The test involves inserting a needle through the abdominal and uterine wall into the amniotic sac to extract a sample of amniotic fluid.
  • Ultrasound (also called sonography): a diagnostic imaging technique that uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Ultrasounds are used to view internal organs as they function and to assess blood flow through various vessels.
  • Blood test

Causes of anencephaly

Anencephaly appears to be caused by a combination of genetic and environmental factors. The interaction of these factors interrupts the closure of the neural tube, which occurs between the third and fourth week of pregnancy.

The specific characteristics of the factors that act in anencephaly and other neural tube defects are not yet well understood. Although we do not know the precise causes of anencephaly, some risk factors have been identified, including an inadequate intake of folic acid .

Folic acid and neural tube defects

There is evidence that having an adequate intake of folic acid before conception will reduce the risk of having a baby affected by any neural tube defect, although the reasons for this are not well understood.

This is why doctors recommend that all women of childbearing age take folic acid supplements and eat folate-rich foods on a regular basis. Don’t wait until you are pregnant. Many obstetricians recommend starting a folic acid supplement at least three months before becoming pregnant.

That being said, anencephaly can occur even when mothers eat a perfect diet, so it cannot necessarily be prevented and it is definitely no one’s fault when it occurs.

In fact, a 2015 study evaluating the prevalence of neural tube defects such as anencephaly in Europe found that there was no reduction in the incidence of these defects, despite widespread recommendations to increase folic acid that have been in place. for several decades.

On the other hand, both the occurrence and severity of spinal neural tube defects (spina bifida) seem to decrease in regions of the world where food is regularly supplemented with folic acid.

Genetic mutations

Learning about gene mutations that can increase the risk of anencephaly is only beginning. Talking to a genetic counselor can help you determine if heredity may have played a role.

However, with that said, a hereditary pattern can only mean that there is a predisposition to neural tube defects, not that these changes cause neural tube defects.

Other risk factors

Other factors that may play a role in the development of anencephaly include socioeconomic status, educational status, maternal age, and environmental factors in addition to folic acid.

There is currently an ongoing investigation in Washington state evaluating a group of babies with anencephaly and looking for possible causes, whether they are genetic (related to variants in the folic acid pathway), exposure to environmental or occupational toxins, and more.

The risk of recurrence

Parents who have a child with anencephaly may have a four to ten percent risk of having a child affected by neural tube defects in a future pregnancy, although the specific neural tube defect may not be anencephaly.

Doctors may recommend taking high doses of folic acid before conceiving again and may recommend that the couple work with a genetic counselor as well.


The decision of what to do after an anencephaly diagnosis can be heartbreaking. Many parents decide to terminate the pregnancy after receiving a diagnosis of anencephaly, knowing that there is no chance for the baby to live.

Ending the pregnancy can help parents move forward and begin the grieving process. Neural tubes are one of the reasons why pregnancy can end for medical reasons.

Other parents may have strictly religious or other personal beliefs against abortion, and may choose to carry the pregnancy to term with the full knowledge that the baby will not live for more than a few days at most.

If you are faced with this tragic choice, be sure to take the time to make a decision and do what is right for you and your partner.

Coping when the baby is diagnosed

It’s okay to be angry, sad, or to experience any other feelings. Your hospital may have grief counselors available, and there are numerous support groups available online that target couples facing a diagnosis of anencephaly.

Anencephaly support groups tend to be geared toward a specific course of action for dealing with pregnancy, whether it means ending the pregnancy or carrying it to term, so you may need to search around to find the one that works best. suits your needs.

For relatives and friends of parents

If you are a family member or friend of someone facing a pregnancy with anencephaly, your loved one will need all the support you can provide. Any form of loss, whether it means miscarriage, death, or the death of a newborn, is difficult, but anencephaly adds one more dimension.

Hearing about folic acid can lead parents to blame themselves, and possible approaches are emotionally charged, like trying to choose between a right turn into large white shark-infested waters, or a left turn into a river. full of crocodiles.

As a very helpful suggestion, try NOT to bring up the possible causes of anencephaly with your loved one. These questions are important, but they should be left to those investigating the causes, not the grieving mother. You can be sure that your loved ones have already tortured themselves enough with the possible causes.

For the same reason, don’t bring up topics like the risk of a neural tube defect reoccurring. Your loved ones are hurting, and they need this moment to deal with their very real pain today.

Lastly, even if you made a different choice if this was your own pregnancy, for example if you choose to go to term and your loved one chooses to terminate, or if you would but your loved one is choosing to go to term, remember this It is not your decision to make.

And hopefully, you will never have to make this decision for yourself, as, as is well known, people often state that they would choose a treatment when looking at a disease from afar, but choose a different approach when faced with the same. decision in real life.

Your loved ones need to make the decision that is best for them, not someone else. Regardless of your choice, they need your full support and care.