Neural tube defects (NTDs) affect 2.6 per 1000 births, with spina bifida and anencephaly accounting for 95% of all NTDs.

Anencephaly is the absence of cranial bones with exposed rudimentary brain tissue. Polyhydramnios is commonly associated with anencephaly due to the absence of pituitary control over urine formation.

Anencephaly is prevalent in low socioeconomic strata due to the lack of folic acid supplementation during pregnancy.