Neural tube defect (NTD)

Abnormal development during embryonic life of the neural tube, the structure which gives rise to the central nervous system (the brain and spinal cord), resulting in anencephaly (absence of the cranial vault and absence of most or all of the cerebral hemispheres of the brain) and spina bifida/meningomyelocele (open spina with exposure and protusion of the spinal cord). The risk of NTDs can be decreased by the mother eating ample folic acid during pregnancy.