What is Anencephaly? Symptoms, Causes, and Prevention

Anencephaly is a congenital disorder that affects a baby’s brain and skull development. Babies with this condition are born missing parts of their brain or skull. It primarily impacts the nervous system, including the brain, spine, and nerves. The neural tube, responsible for forming the brain, skull, spinal cord, and backbones, plays a crucial role in early fetal development. “Failure of the neural tube to close in the early weeks of pregnancy results in a condition called anencephaly. This condition falls under cephalic disorders and is classified as a neural tube defect.

The brain regulates vital body functions, manages memory, and governs emotions, playing an essential role in human survival. Anencephaly disrupts brain development in an unborn baby, leading to an incomplete brain formation or missing skull bones at the back, front, and sides of the head. Babies with this condition have no chance of survival, often living only for a few minutes, hours, or days. Most pregnancies affected by anencephaly result in miscarriage or stillbirth.

Types

Anencephaly has three types, all of which are fatal for the fetus:

• Meroanencephaly: The brainstem and midbrain develop partially, with some skin and skull covering the brain.
• Holoanencephaly: The brain fails to develop entirely, making it the most common form of anencephaly.
• Craniorachischisis: The brain, skull, and spine do not develop, making it the most severe type.

Symptoms

Anencephaly cannot be detected unless a blood test of the birthing parent is done or an ultrasound is performed. Newborn babies with anencephaly have:

• No bones at the back, front, or side of the head
• Large areas of the brain are missing
• Folding of the ears
• Congenital heart defects like structural problems with the chambers, walls, and valves
• No consciousness and ability to feel pain
• No vision or hearing
• Cleft palate: An opening can extend into the nasal cavity
• Smaller head size

Newborns with anencephaly may or may not develop a brain stem. If the brainstem is present, the baby may have reflexes and respond to touch. This may give parents hope, but they cannot live with the condition for long.

Causes

Anencephaly is caused by a problem with how the neural tube forms and closes. During the third and fourth week of pregnancy, the brain and spine begin to develop as a flat plate of cells. This plate folds to form a structure known as the neural tube. This tube is completely formed in a normal child 28 to 32 days after conception. An opening remains if the neural tube does not fully close, either partially or completely. It is possible that the opening in the tube can be left exposed or covered with bone and skin. Failure of the neural tube to seal at the base of the skull results in a condition known as anencephaly.

Some neural tube defects may be caused by genes passed on from both parents. Sometimes, it could be caused by environmental factors such as obesity, uncontrolled diabetes in the mother, and certain prescription medicines. In many cases, it has been seen that babies with neural tube defects do not have any family history of this problem.

Prevention and Diagnosis

The diagnosis of anencephaly must be made during pregnancy. Tests can include:

• Quad Marker Screen: A blood test of the mother’s blood called a quad screen can check for a neural tube defect or other problems. The test must be done between 16 and 18 weeks of pregnancy. It measures levels of alpha-fetoprotein (AFP), a protein made by the baby’s liver growing in the womb. High levels of this protein leak into the mother’s blood and show the presence of anencephaly.
• Prenatal Ultrasound: A diagnostic procedure that employs high-frequency sound waves and computer technology to create images of organs, tissues, and blood vessels. A healthcare provider can observe the organs as they function using an ultrasound. Since an ultrasound also shows blood flow, it can detect an open neural tube defect.
• Amniocentesis: Amniocentesis involves testing a small sample of the amniotic fluid around the baby for AFP levels. A healthcare provider inserts a long, thin needle into the amniotic sac to collect this fluid.
• Fetal Magnetic Resonance Imaging (MRI): An MRI scan employs strong magnets to generate detailed images of bones and tissues. These images can provide greater detail about the baby’s brain and spine.

If the diagnosis is made after birth, the baby’s head appears flattened because of the abnormal brain growth and missing skull bones.

Prevention of anencephaly may not always be possible, but you can reduce the possibility of having a child with this defect by doing a few things:

• Getting plenty of folic acid: Since the neural tube closes 28 to 32 days after the baby is conceived, many women are unaware that they are pregnant at this stage. However, if you are planning to conceive, you can start taking folic acid. Folic acid (Vitamin B9) is found in leafy green vegetables, nuts, beans, citrus fruits, and fortified breakfast cereals.
• Medication: If you are planning to conceive, talk to your healthcare provider about the medications that you are taking. Certain medicines that regulate seizures can cause neural tube defects.
• Managing your health: If you’re planning to conceive and have health issues such as diabetes, consult your healthcare provider to manage these conditions and maintain good health.
• Stop drinking: Avoid alcohol or being around hazardous chemicals.
• Use opioids: Taking opioids during the first two months of pregnancy increases the risk of neural tube defects (NTDs). This includes substances like heroin and prescription pain medications such as hydrocodone.

Impact and Support

The outlook for anencephaly is very poor, and most babies with the condition pass away before birth, or the pregnancy ends in miscarriage. If born, the baby may die within a few minutes, hours, or days of birth. You may worry about your baby’s pain, distress, or discomfort. However, babies with anencephaly cannot feel pain, think, or respond.

Knowing that your baby has anencephaly can be very difficult for the parents. It is important to seek help to say goodbye to your baby and bear the loss of a child. You must find support and someone to talk to. Finding a counselor for bereavement and grief will be crucial. There are support groups that can also help. Therapy can support you in coping with the loss you are experiencing.

Essential Health Tips for a Safe Pregnancy

Before trying to conceive, speak with a healthcare provider to ensure optimal health and decrease the chance of birth defects. If you are pregnant and experience symptoms of a miscarriage, such as heavy bleeding, cramps, or back and abdominal pain, seek immediate medical attention.