Anencephaly is a form of neural tube defect (NTD) that hampers the normal brain and skull development . Babies affected by this condition are often stillborn or die within a few hours or days of birth.
The neural tube, a narrow layer of cells, ideally folds and closes in the first month (the third and fourth weeks) of pregnancy to form your baby’s brain and spinal cord . Sometimes, the head end (anterior neuropore) of the tube fails to fold and close, leading to the lack of major parts of the brain and skull.
Doctors still do not know the exact causes responsible for anencephaly as various genetic and environmental factors are believed to contribute to this congenital defect. Several risk factors have been identified, including:
Following a healthy diet rich in various vitamins and minerals, especially folic acid, as soon as you plan to conceive or at least as soon as you find out you are pregnant can help to reduce the chances of having a child with anencephaly . It is recommended to take a folic acid supplement daily as most women do not get the recommended amount (400 mcg)  of the vitamin from their regular diet.
Although, in most cases it is not diagnosed before the 15th and 18th week, it is possible to detect the defect much earlier (10th to 12th week) . However, sometimes it is not possible to confirm the diagnosis before the baby is born.
The characteristic physical symptoms are enough for making and confirming the diagnosis after the baby is born .
There are no treatments for the absent or under-developed brain . Aggressive resuscitation is not provided in many cases as it is not possible for the baby ever achieving a normal and conscious existence.
Doctors often recommend termination of pregnancy when the diagnosis is confirmed at the prenatal stage. Many anencephalic babies carried to full term do not even survive birth. Those who do are provided with clinical measures like nutrition, hydration and feeding assistance while their exposed brain areas are protected as well. Artificial ventilation, drug therapy (e.g. antibiotics) and surgery for correcting any organ defects are often regarded futile by physicians .
The survival rate is remarkably low with 7% of the affected babies dying in the womb, 20% dying during delivery and 50% living for only a few minutes to a day. The life expectancy for the rest (23%) of the patients ranges from a few days to a few weeks .
It is considered the most common neural tube defect along with spina bifida, occurring in about 1 out of every 1,000 pregnancies. However, its prevalence in newborns is quite low as most women carrying an anencephalic child suffer miscarriage. In the United States, the incidence is estimated to be around 1 in 10,000 .
In some very rare cases, the babies survive for a few months to years, with the longest survivors including Nickolas Coke (3 years 11 months) from Pueblo, Colorado and Vitoria de Cristo (2 years five months) from Brazil .
Ninety percent of infants born with anencephaly do not have any family history of this disorder. However, hereditary factors may play a role in some cases as parents who already had a baby with the condition are 4%-5% more likely to have another affected pregnancy . The recurrence risk rises to 10%-13% with couples who had two babies with the defect.
There is no substantial risk of complications for the mother, apart from premature contractions, water breaking and labor due to the polyhydramnios associated with anencephaly . But the emotional distress is great for both parents.
The ICD-9 code used for the condition is 740.0  while its ICD-10 code is Q00.0 .
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