Strategies for Prevention of Neural Tube Defects

of enriched grain product with folate is not compulsory or endorsed officially, was 5.32 per 10,000 live births (Annual report 2007(Annual report with data 2005(Annual report , 2009)).The primary objective of this review article is to discuss the strategies for prevention of NTDs. Definition and classificationNTDs are common and severe congenital malformations of the central nervous system occurring secondary to a lack of closure of the neural tube.The following three groups are categorized based on the severity of the defects (Copp & Harding, 2004). Severe formThe severe form of the NTD spectrum includes open defects resulting from the failure of neural tube closure, in which the interior of the brain or spinal cord communicates directly with outside, and includes the following:Craniorachischisis: There is an almost complete absence of neural tube closure, affecting both the brain and spine.This malformation results from a failure of the initiating event of neurulation in the early embryo. Excencephaly: This is a brain defect resulting from a failure of cranial neural tube closure.Although this appearance is seen only in embryos and early fetuses, the persistently open cranial neural folds have an everted appearance. Anencephaly: Exposed cranial neural folds may degenerate with advancing gestation.This is a catastrophic malformation in which the brain is severely degeneratd and the skull vault is absent. Myelomeningocele: This results from a failure of the closure of the spinal neural tube, most often in the lumbosacral region.In spina bifida cystica, a meningeal sac containing the open spinal cord herniates through a vertebral defect.In myeloceles, the open spinal cord is directly exposed as a flat open lesion. Moderate formThe moderate form of NTD includes encephaloceles and meningoceles.These defects result from herniation of the brain or meninges through an opening in the skull or vertebral column, respectively.These defects appear to be primary abnormalities of skeletal development, not neural tube closure, as the brain and spinal cord appear to have closed normally prior to herniation. Mild formThe mild end of the NTD spectrum is represented by a third group of dysraphic defects in which there are closed abnormalities of the spinal cord, usually in the low lumbar and sacral regions.The following types are included: Diplomyelia: This is a side-by-side or anteroposterior duplication of the spinal cord. Diastematomyelia: A midline septum divides the spinal cord longitudinally into two usually unequal portions extending up to 10 thoracolumbar segments. Hydromyelia: The central canal is overdistended (Fig. 1).