Anencephaly occurs when the neural tube, which forms the brain and spinal cord, fails to close properly during the first month of pregnancy, resulting in the brain and skull not developing properly. In the absence of or incomplete formation of the cerebral cortex, the part of the brain responsible for thinking, movement, and senses, anencephaly babies usually die in the first few hours, days, or even weeks following birth.
The exact cause of anencephaly is unknown, but it may involve a combination of genetic and environmental factors. Some possible risk factors include:
Low intake of folic acid, a vitamin that helps prevent neural tube defects, before and during pregnancy.
Exposure to high temperatures, such as from fever, sauna, or hot tub, during early pregnancy.
Diabetes, obesity, or other medical conditions that affect the mother’s health and metabolism.
Certain medications, such as those used to treat epilepsy or acne, that may interfere with the neural tube development.
Having a previous pregnancy affected by anencephaly or another neural tube defect.
During pregnancy, anencephaly can be detected through blood tests, ultrasounds, or amniocentesis. Alpha-fetoprotein, a protein produced by the fetus, is usually elevated in anencephaly cases, and can be measured with these tests. In addition to showing skull and brain abnormalities, they can also reveal missing or exposed parts.
Babies with anencephaly have the following symptoms at birth:
Small or missing parts of the skull and brain, which may be covered by skin or not.
Lack of consciousness, vision, hearing, and pain sensation.
Difficulty breathing, feeding, and regulating body temperature.
Seizures, spasms, or other abnormal movements.
Care is offered to the baby and the family based on the parents' wishes and the baby's condition. Depending on the parents' wishes and the baby's condition, some options include:
Continuing the pregnancy and delivering the baby naturally or by cesarean section.
Terminating the pregnancy if the diagnosis is made early enough and the laws allow it.
Donating the baby’s organs or tissues for transplantation or research, if possible and desired.
Providing palliative care, such as pain relief, hydration, and warmth, to the baby after birth.
Seeking counseling, spiritual guidance, or support groups to cope with the grief and loss.
Anencephaly can cause serious complications for the baby and the mother, such as:
Bleeding, infection, or rupture of the uterus or placenta.
Preterm labor or delivery.
Excess amniotic fluid or placental abruption.
Emotional distress, depression, or anxiety.
It is recommended that women who are planning to conceive or who are pregnant take 400 micrograms of folic acid per day in order to prevent anencephaly. If their previous pregnancy was affected by anencephaly or another neural tube defect, they should take a higher dose of 4 milligrams per day, as prescribed by their doctor.
Other preventive measures include:
Avoiding exposure to high temperatures, such as from fever, sauna, or hot tub, during early pregnancy.
Controlling diabetes, obesity, or other medical conditions that affect the mother’s health and metabolism.
Consulting with a doctor before taking any medications, especially those that may interfere with the neural tube development.
Having regular prenatal check-ups and screenings to monitor the fetal growth and development.
When a baby has anencephaly, their outlook is very poor, as they usually die after birth, are stillborn, or are miscarried. Anencephaly and other neural tube defects have a recurrence rate of 4 to 10 percent in the next pregnancy, and about 10 to 13 percent in subsequent pregnancies. Before planning another pregnancy, parents of anencephaly babies should consult with a genetic counselor or specialist.
