Anencephaly

Anencephaly is a head and brain disorder that results from what's known as a neural tube defect. This is what happens when the neural tube in early pregnancy fails to close between the twenty third and twenty sixth day of pregnancy, so that most of the brain, skull and scalp are missing from the top and back of the head. The baby looks deformed and has a deformed head. The children are missing the cerebral hemispheres so they cannot have any higher level cognition or thinking and can have exposure of the underlying brainstem which isn't covered by any bone or any skin.

The child born with anencephaly is unconscious, blind and deaf; they are unable to feel any pain. Some will be born with a brainstem and some will not. Without a brainstem, they cannot breathe on their own and are stillborn. Some reflex ability is noted.

The cause of anencephaly depends on the pregnancy. Some anencephaly is inherited and a woman who has a child with one neural tube defect has a three percent chance of having another child with a neural tube defect. Women who are insulin dependent with diabetes have an increased risk of anencephaly and women with epilepsy who take certain medications have a greater risk of anencephaly in their children. Women who do not take enough folic acid during pregnancy have a higher than average risk of getting a child with anencephaly. This is why prenatal vitamins contain higher than normal amounts of folic acid. It is recommended that a woman take 0.4 mg of folic acid every day during the pregnancy or when trying to conceive. This reduces the overall risk of anencephaly to 0.03 percent.

It is important to take the folic acid before you know you are pregnant because it needs time to build up and have its effectiveness in improving neural tube defect closing. Even higher doses are recommended for women who have had previous neural tube defects in prior pregnancies.

Anencephaly has been related to exposure to heavy metals such as lead, mercury, nickel and chromium around the time of pregnancy. Exposure to depleted uranium is dangerous for pregnant women and can lead to neural tube defects like anencephaly.

The diagnosis of neural tube defects such as anencephaly can be done in utero using an ultrasound during the pregnancy which can show the lack of a cranium. A serum alpha fetoprotein test or AFP test can indicate the presence of a neural tube defect. It can detect both spina bifida and anencephaly.

There is no cure or regular treatment for anencephaly. The vast majority of infants die at birth or shortly thereafter. Most do not survive the birth process and account for 55 percent of non-aborted cases. If the infant is not directly stillborn, the baby will likely die a few hours or a few days following its birth. They die because of cardiorespiratory arrest. They do not have the ability to breathe well on their own and their brainstem gives out.

Doctors rarely resuscitate anencephalic babies because they have no quality of life and no way of preventing the brainstem of later becoming infected. The infant is unconscious and the brain never develops after birth. The goal of treating anencephaly is to hydrate, nourish and provide comfort to the infant until nature takes its course and the infant dies of natural causes. Artificial ventilation is sometimes provided but, in most cases, the infant is allowed to die in whatever way is most natural. Even hydration and nutrition are considered medically futile therapies and can be withheld depending on the family's wishes.

The incidence of anencephaly is rare. It occurs in about one out of every 150,000 to 200,000 infants born in the US. Female babies are disproportionately affected when compared to male babies.