Iniencephaly

What is iniencephaly?

Iniencephaly is a rare congenital condition (meaning babies are born with it) of the head, neck and spine. Babies with iniencephaly are born with a shortened or absent neck, upturned head and malformed spine. Often, your baby has abnormalities in other body systems.

Most babies with iniencephaly die before or shortly after birth. Though it is very uncommon, a baby with mild iniencephaly can survive long term.

How common is iniencephaly?

Iniencephaly was first reported in 1836 by a French scientist named Isidore Geoffroy Saint-Hilaire. Current estimates of how often iniencephaly occurs vary widely. Healthcare providers believe that between 1 and 100 of every 100,000 babies born have iniencephaly. The condition is more common in people assigned female at birth.

How does iniencephaly occur?

Iniencephaly is a neural tube defect, which is a birth defect of the nervous system. During fetal development, the neural tube gives rise to the brain, spine and spinal cord.

The neural tube forms and closes between the third and fourth weeks of pregnancy. In iniencephaly, something disrupts this process, and the nervous system doesn’t develop correctly.

What causes iniencephaly?

The exact cause of iniencephaly is not known, but it’s likely a combination of genetic and environmental factors. Providers have linked chromosomal abnormalities such as monosomy X and trisomy 13 and 18 to some cases of iniencephaly. Environmental factors that may increase the chance of having a baby with iniencephaly include:

• Lack of folic acid.
• Alcohol use.
• Smoking.
• Diabetes.
• Obesity.
• Use of certain drugs during early pregnancy (sulfa drugs, certain antiseizure drugs, diuretics and antihistamines).

If you had a previous pregnancy with a neural tube defect, you are also at higher risk of having a baby with iniencephaly.

How is iniencephaly diagnosed?

At birth, healthcare providers diagnose iniencephaly by the appearance of the skull and spine. If the baby survives, the provider can use ultrasound, CT scan and MRI tests to evaluate the condition and determine treatment options.

Can iniencephaly be diagnosed before birth?

During pregnancy, several tests can indicate whether your baby might have a neural tube defect. Your healthcare provider may order these tests as part of routine screening or if your pregnancy is at higher risk:

• Prenatal ultrasound: This imaging test uses sound waves to create pictures of the developing baby. Your provider uses a prenatal ultrasound to look at your baby’s head, neck and spine.
• Quad marker screen: This is a test of the mother’s blood for several hormones and proteins. One of the proteins in the quad marker screen is alpha-fetoprotein (AFP). The baby makes AFP, which passes into the mother’s blood. A high level of AFP in the mother’s blood could mean the baby has a neural tube defect.
• Amniocentesis: In amniocentesis, a provider uses a thin needle to collect a small amount of amniotic fluid that surrounds the baby. The lab measures AFP levels and performs karyotype testing on the amniotic fluid to check for chromosomal abnormalities. Both tests can indicate a neural tube problem, and its cause.
• Fetal MRI: This imaging test uses radio waves and a strong magnetic field to produce more detailed images of the baby’s bones and tissues. MRI scan does not pose radiation risk to the baby.

It’s critical to identify iniencephaly as early as possible. Early identification allows healthcare providers to counsel families about their baby’s condition and provide care for the parent(s). If the pregnancy continues to term, the deformities can pose a risk to the birthing parent during childbirth.

How is iniencephaly treated?

There is no treatment for iniencephaly. Nearly all babies with iniencephaly die during pregnancy or shortly after birth. Providers work with families to help them cope with the loss of a child.

For the very few babies that do survive, healthcare providers treat them on a case-by-case basis.

Can folic acid prevent iniencephaly?

The main thing you can do to prevent neural tube defects, including iniencephaly, is to take folic acid before and during pregnancy. Folic acid is a B vitamin that your body uses to make new cells.

Researchers have found that 400 micrograms of folic acid per day can reduce neural tube defects by 70%. People of reproductive age who were assigned female at birth should take this amount of folic acid daily because:

• Many pregnancies are unexpected.
• Neural tube defects occur before most people even know they’re pregnant.

If you're in your childbearing years, talk to your healthcare provider about folic acid. If you're planning a pregnancy, ask your provider to prescribe a specially formulated prenatal vitamin that includes folic acid.

People who've had a child with a neural tube defect and are planning another pregnancy need more folic acid. The U.S. Centers for Disease Control and Prevention (CDC) recommends 400 micrograms of folic acid starting one month before becoming pregnant through the first three months of pregnancy. Taking high levels of folic acid can be harmful. Consult your provider before increasing your folic acid.

What else can I do to reduce the risk of iniencephaly?

You can also lower the risk of iniencephaly by:

• Avoiding certain drugs that are linked to neural tube defects.
• Eliminating alcohol use.
• Maintaining a weight that's healthy for you.
• Managing diabetes.
• Quitting smoking.

What is the outlook for iniencephaly?

Iniencephaly is a complex genetic condition and, in most instances, the outlook is poor. Pregnancies most often end in a miscarriage or stillbirth. If a baby is born alive, it will likely die within hours after birth.

As of 2019, only eight known babies with iniencephaly have survived long term. Four of these patients required surgical treatment and had successful outcomes.

How do I plan for a healthy pregnancy?

During your childbearing years, you should take 400 micrograms of folic acid each day, even if you’re not trying to get pregnant. Nearly half of pregnancies are unplanned. Folic acid can prevent neural tube defects, including iniencephaly, which occur before most people know they’re pregnant.

People planning a pregnancy should schedule an appointment with their healthcare provider for preconception counseling. At this visit, your provider will review all your risk factors and recommend steps you can take for a healthy pregnancy.

A note from Cleveland Clinic

Neural tube defects, including iniencephaly, aren't always preventable. The best thing you can do is adopt a healthy lifestyle and make sure you're getting enough folic acid. People assigned female at birth who are of childbearing age should take at least 400 micrograms of folic acid daily. If you're planning to become pregnant or have had a child with a neural tube defect, talk to your provider. Together, you can make sure you’re getting enough folic acid and staying healthy.