Hospiten tells us about spina bifida

Spina bifida is a birth defect that occurs when the spine and spinal cord do not form properly, which can lead to damage or defects in the spinal cord itself and the nerve roots. It is also called a “neural tube defect” and results in physical and intellectual disabilities ranging from mild to severe, depending on the size and location of the defect in the spine.

The causes of spina bifida are not all known, but it is believed to be the result of a combination of genetic, nutritional, and environmental risk factors, such as a family history of neural tube defects or folate (vitamin B-9) deficiency. Chromosomal abnormalities, gene mutations, maternal diabetes, obesity, or antiepileptic drugs are implicated in 10% of cases.

How to diagnose spina bifida

Since the mid-20th century, folic acid supplementation has been known to contribute to a decrease in the number of cases. In the 1980s, the incidence was one case per 2,000 live births and has now decreased to one case per 4,000 live births.

Treatment should preferably be initiated one month prior to pregnancy and continued until the end of the first trimester of pregnancy. In high-risk patients, such as those with obesity, diabetes, epilepsy, or a history of spina bifida in previous pregnancies, the dose of folic acid should be higher and it is preferable to start three months before pregnancy, achieving a 75% reduction in recurrence.

For many years, spina bifida was diagnosed by a second trimester blood test that measured a protein called alpha protein, which indicated whether the patient was at risk of having a fetus with spina bifida. Today, such a blood test is no longer routinely performed because of advances in ultrasound, which, in expert hands, achieves a 98% detection rate of spina bifida cases on second-trimester ultrasound around 20 weeks.

In the last decade, advances in first trimester ultrasound have made it possible to perform fetal brain assessment to identify those fetuses at increased risk for neural tube defects, and most fetuses with spina bifida are identified at a much earlier gestational age.

In some cases, fetal chromosomal screening by invasive testing (such as amniocentesis) and more extensive genetic studies may be recommended because in some cases there may be an association with genetic problems.

Ultrasound monitoring of these patients is performed to monitor the development and possible evolution of associated abnormalities, such as increased fluid in the brain.

Treatments of spina bifida

Among the advances in treatment, fetal therapy stands out.

Currently, fetal intervention is performed between 24 and 26 weeks of gestation.  It is a technique that does not cure the defect, but has great advantages in preventing the progressive deterioration of the fetal motor system (mobility of the lower limbs). In addition, this operation reduces the need for a ventriculoperitoneal shunt valve after birth.

Due to the complications of this defect, approximately 20% of infants die in the first twelve months of life and 25% die before birth.

Surviving infants usually have lower limb paralysis and sphincter incontinence; although the associated increased cerebral fluid (hydrocephalus) requires surgery, intelligence is usually normal.