Screening for neural tube defects

Neural tube defects are separated into two main categories: (1) abnormaliti es of the skull and brain (anencephaly, acrania, and encephalocele) and (2) malformations of the spine (merningomyelocele or spina bifida). The cause of neural tube defects is not always clear, and include chromosomal abnorma lities, single gene mutations, maternal disease, or maternal exposure to te ratogens. Mostly the disorder emerges as a multifactorial trait. Routine sc reening for neural tube defects was introduced in the United Kingdom in the mid-1970s and the United States in the mid-1980s. The use of screening has resulted in a marked decline in the frequency of neural tube defects diagn osed at birth.