Analysis of midtrimester amniotic fluid for detection of open neural tube defects and ventral wall defects Test Includes Detection of AChE. The reflex to fetal hemoglobin (Hb F) will be performed, if necessary, to ascertain false elevations of amniotic fluid AFP.
Specimen Sources
Amniotic Sac
Specimen Types
Amniotic Fluid
Container
Sterile
Collection Instructions
Container/Tube: Sterile Plastic container or vial. Do not use urine containers or tubes with rubber stoppers. Rubber is toxic to amniocytes. Specimen 3 mL Amniotic Fluid Transport Temperature: Room Temperature Specimen Stability: Room Temperature 6 days Patient Preparation The patient should have undergone ultrasound studies to verify fetal viability, detect multiple gestation, confirm gestational age, localize placenta, and detect fetal and uterine pathology. Collection Avoid contamination of amniotic fluid with maternal or fetal blood. As little as one drop of fetal blood can cause false-positive results during assay of amniotic fluid. Amniotic fluid should be collected by the attending physician.
Transport Instructions
Specimen Stability
Amniotic fluid supernatant samples are stable at ambient temperature for 6 days.
Additional Information: 1. Indications for Testing: Suspicion of Open neural tube defect due to elevated Amniotic Fluid AFP or ultrasound findings.
Methodology
Acrylamide gel electrophoresis; isoelectric focusing (IEF)
