Rachischisis

Overview

Rachischisis is a severe birth defect in which the spine and spinal cord are left open, with the nervous tissue exposed along part or much of the back. It is one of the most serious forms of neural tube defect, a group of conditions caused by failure of the neural tube, the early structure that forms the brain and spinal cord, to close during the first weeks of pregnancy.

In rachischisis, the failure of closure extends over a long segment of the spine, so the bony arches do not form and the spinal cord remains unprotected. The most severe forms are not compatible with survival. Because these defects share causes with conditions such as spina bifida and anencephaly, the same preventive steps, especially adequate folic acid before and during early pregnancy, apply.

Features

Rachischisis is usually identified before birth on prenatal imaging. Its features include:

• An open, exposed segment of spinal cord along the back, without overlying skin or bone
• A long defect that may extend over much of the spine
• Often associated with other neural tube defects, such as anencephaly
• Severe neurological impairment below the level of the defect when an infant survives

Because the spinal cord is exposed and the defect is extensive, the most severe forms carry a very poor prognosis, and many affected pregnancies end in miscarriage or stillbirth.

Causes

Rachischisis results from failure of the neural tube to close along the spine early in pregnancy, often before a person knows they are pregnant. The exact cause in an individual is usually unknown and reflects a mix of genetic and environmental factors. Contributing factors include:

• Low folic acid (folate): Insufficient folate around conception is a major, preventable risk factor.
• Genetic factors: A family or personal history of neural tube defects increases risk.
• Certain medications and conditions: Some anti-seizure medicines and poorly controlled diabetes raise the risk.
• Other factors: Obesity and high body temperature in early pregnancy have been linked to neural tube defects.

Risk Factors

• Inadequate folic acid before and during early pregnancy
• A previous pregnancy affected by a neural tube defect
• A family history of neural tube defects
• Poorly controlled diabetes before pregnancy
• Use of certain anti-seizure medications
• Obesity in the parent carrying the pregnancy

Diagnosis

Rachischisis is typically detected during pregnancy through routine prenatal care:

• Maternal blood screening: Elevated alpha-fetoprotein (AFP) can suggest an open neural tube defect.
• Ultrasound: Detailed ultrasound can show the open spine and any associated defects, often in the second trimester.
• Fetal MRI: Occasionally used to define the extent of the defect.

A diagnosis allows families to receive counseling and support and to plan care with their team.

Care and Support

There is no treatment that can reverse the most severe forms of rachischisis, so care centers on the family and, where applicable, the infant's comfort.

• Counseling and support: Genetic counseling, clear information, and emotional support help families understand the diagnosis and options.
• Pregnancy and delivery planning: The team helps families plan in line with their wishes and values.
• Comfort-focused care: For infants who survive birth, care emphasizes comfort and dignity.
• Bereavement support: Ongoing support is offered to grieving families.

Less extensive open-spine defects may be managed like severe spina bifida, with specialized surgical and supportive care.

Prevention

Many neural tube defects can be reduced with adequate folic acid:

• Take a daily folic acid supplement before conception and in early pregnancy; higher doses may be advised for those at increased risk
• Eat folate-rich foods such as leafy greens, beans, and fortified grains
• Control diabetes before becoming pregnant
• Review medications with a doctor before pregnancy
• Seek genetic counseling if you have had a previous affected pregnancy

When to See a Doctor

If you are planning a pregnancy or could become pregnant, talk to a doctor about folic acid and personal risk factors, ideally before conception. During pregnancy, attend all recommended prenatal visits and screenings. Seek prompt advice if you:

• Have a personal or family history of neural tube defects
• Take medications that may affect a pregnancy
• Have diabetes or another condition that needs control before pregnancy
• Receive an abnormal screening result and need counseling and support

Related Topics

Frequently Asked Questions

References

1. Centers for Disease Control and Prevention (CDC). Neural Tube Defects.
2. MedlinePlus, U.S. National Library of Medicine. Neural tube defects.
3. March of Dimes. Neural tube defects.
4. National Institute of Neurological Disorders and Stroke (NINDS). Spina bifida.