Increased acetylcholinesterase in amniotic fluid indicates -

(A) (Open neural tube defects) (1998 - Nelson 19th)* Failure of closure of the neural tube allows excretion of fetal substances (a-fetoprotein , acetylecholinesterase) into the amniotic fluid, serving as biochemical and markers of a neural tube defects (NTD).* Prenatal screening of maternal serum of AFP in the 16th - 18th week gestation is an effective method for identifying pregnancies at risk for features with NTDA in utero.* Risk factor for neural tube defects (william obs)i) Family history of NTD-First degree relative 2 - 3% Autosomal dominant or Autosomal recessive - 20 - 3% times highter.ii) Exposure to certain environmental agents, malnutrition.iii) Diabetes (Hyper glycemia/Matemal obesity).iv) Hyperthermiav) Drugs - valproic acid, carbamazepine, Aminopterin and isotretinoin (Anacephaly or encephalocele)vi) Genetic syndrome with known recurrence risk Meckel - Gruber, Roberts - SC, Phocomelia, Jarco Levin and HARDE syndrome.vii) Trisomy 13 and 18 and Triploidy all have 1% recurrence risk.* Major NTDs include - spina bifida occulta, meningocele, myelomeningocele, encephalocele, anencephaly, caudal regression syndrome, dermal sinus, tethered cord, syringomyelia, diastematomyelia and lipoma involving the conus medullaris and / or filum terminale and the rare condition anencephaly.Prevention - The U.S. Public health service has recommended that all women of child bearing age and who are capable of becoming pregnant take 0.4 mg folic acid daily.* Nuchal translucency is used for screening of Down syndrome in antenatal USG**