Spina Bifida

Sneha Ingle -

During pregnancy, a number of routine tests are done to inspect the health of the fetus. One such test checks for spina bifida, a condition where the fetus has an unclosed neural tube. During typical fetal development, the neural tube completely closes to encase the brain and spinal cord. As a result of the open neural tube, a baby born with spina bifida can suffer from conditions like hydrocephalus, where excess fluid in the skull puts pressure on the brain; meningitis, an infection of the brain and spinal cord that causes inflammation; and occasionally paralysis, due to the exposure of the spinal cord [1]. Regrettably, this condition affects nearly 1500 babies a year in the United States [2].

At present, there are two pre-natal tests used to screen for spina bifida. Doctors routinely check for high levels of alpha-fetal protein in the mother’s blood and amniotic fluid, which may indicate spina bifida [3]. Additionally, under ultrasound the fetal spine can be closely examined for structural abnormalities that are visible as early as 16-23 weeks [4]. Less severe forms of spina bifida, however, cannot be detected prenatally so after birth, the child’s spine is also examined. Indeed, some forms of the disease may not be identified until late childhood, due to the relatively low impact they can have on the child’s life [3].

Causes of spina bifida have not yet been fully identified, though as with many conditions, it is likely that genetic and environmental factors work together to cause this condition. One well studied environmental factor is maternal deficiency of the B vitamin folic acid. Because we do not endogenously synthesize folic acid, it is critical to obtain it through a well-balanced diet. In 1998, cereal manufacturers were required to fortify their product with folic acid and as a result, spina bifida births decreased by 31% per year [2][5]. Because spina bifida is a neural tube defect, it occurs early in development – often before pregnancy can be detected. This makes it slightly more challenging to ensure that pregnant women take folic acid, as many might not realize they are pregnant until it’s too late for the vitamin to be of use. Therefore, the American Medical Association recommends that all women of childbearing age take folic acid supplements, whether they are pregnant or not, in an attempt to combat the range of fetal birth defects that arise from folate deficiency [3].

The prognosis for patients diagnosed with spina bifida depends on the severity of the disease. In some cases, individuals with spina bifida may exhibit such minor symptoms that they are not diagnosed until well into early adolescence. In other cases, however, patients with spina bifida may experience more severe impairments, ranging from physical problems such as paralysis to intellectual and developmental disabilities [3]. Recent research has given us not only a better idea of how spina bifida can be prevented, but also how those diagnosed with even some of the more severe forms of this condition can live happy and healthy lives.

References

  1. CDC. (2015). Living With Spina Bifida: Infants. Retrieved from http://www.cdc.gov/ncbddd/spinabifida/infant.html
  2. Boulet, S., Yang, Q., Mai, C., Kirby, R., Collins, J., Robbins, J., Mulinare, J. (2008). Trends in the postfortification prevalence of spina bifida and anencephaly in the United States. Birth Defect Res A Birth Defects Research Part A: Clinical and Molecular Teratology, 527-532.
  3. CDC. (2015). Spina bifida - Facts. Retrieved from http://www.cdc.gov/ncbddd/spinabifida/facts.html
  4. Nicolaides, K., Gabbe, S., Campbell, S., & Guidetti, R. (1986). Ultrasound Screening For Spina Bifida: Cranial And Cerebellar Signs. The Lancet,328(8498), 72-74. doi:10.1016/S0140-6736(86)91610-7
  5. CDC. Spina Bifida and Anencephaly Before and After Folic Acid Mandate—United States, 1995-1996 and 1999-2000. (2004). JAMA, 325-325. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/15129193