title: Neural-tube defect risk assessment for individual pregnancies using alphafetoprotein and acetylcholinesterase test results.
abstract: Pregnancies at risk of being associated with (open) neural tube defects can be identified by maternal serum and amniotic-fluid alphafetoprotein (AFP) concentrations in excess of established screening cut-off valves in conjunction with the results of an amniotic fluid electrophoretic acetylcholinesterase screening test. The risk associated with the AFP cut-off values are formulated in terms of a population screening programme. These "population risks" are of little value in the assessment of test results from individual "at-risk" pregnancies, especially when the observed AFP concentrations are in proximity to the "cut-off" values. A complete risk assessment procedure for individual pregnancies is described and presented in graphical form to permit immediate access by clinical staff.
mesh_terms: D000110:Acetylcholinesterase / Q000032:analysis*; D000653:Amniotic Fluid / Q000032:analysis / Q000201:enzymology; D004796:Clinical Enzyme Tests; D005260:Female; D005865:Gestational Age; D006801:Humans; D008433:Mathematics; D009436:Neural Tube Defects / Q000175:diagnosis*; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012306:Risk; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D000509:alpha-Fetoproteins; D000110:Acetylcholinesterase