Test Directory

This test is used to analyze midtrimester amniotic fluid for detection of open neural tube defects and ventral wall defects.

Specimen Type: Amniotic Fluid

Collection Container: Sterile, Non-additive Container

Desired Specimen Volume: 1 mL

1. Collect amniotic fluid in a sterile container.
2. Avoid contamination of amniotic fluid with maternal or fetal blood.

**Requires Integrated Genetics Test Requisition**

1. Transfer 1 mL of amniotic fluid in the original collection container.
2. Include the gestational age by ultrasound and/or last menstrual period (LMP) on the request form on the date of draw of the sample.

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.

The patient's gestational age must be between 12 weeks and 24 weeks for interpretation of α-fetoprotein.

Transport to the laboratory refrigerated. 

• Tubes with rubber stoppers
• Gross contamination of amniotic fluid with maternal or fetal blood

 See patient report.

Note that AChE false-positive and false-negative results are more frequent at gestational ages less than 13 weeks or greater than 24.9 weeks. Optimal gestational age is 14 to 18 weeks.