Amniotic Fluid- Cell Count

Sample type:

• Amniotic, amniocentesis fluid.

• Sterile container or lavender-top (EDTA) tube or green-top (heparin) tube

Uses:

• Evaluate amniotic fluid for the presence of RBCs (semiquantitative), WBCs, differential, and for physical appearance

Precautions:

Prior to amniocentesis, an ultrasound examination should be performed.

Ultrasound examination is used to:

• Confirm fetal gestational age

• Detect gross fetal anomalies

• Verify fetal cardiac activity

• Determine placental location

• Determine volume of amniotic fluid

• Determine the number of gestational sacs

• Determine the correct abdominal puncture site

Interfering Factors:

• Leukocyte (WBC) count is often of limited value; however, amniotic fluid infection or chorioamnionitis is usually associated with polymorphonuclear leukocytosis (>100/μL).

• Controversy exists in the literature concerning the significance of the presence of leukocytes in amniotic fluid.

• Some studies reflect the absence of leukocytes and bacteria was associated with a negative amniotic fluid culture in 77.9% to 95% of the patients.

Pre analytical errors:

1. Inappropriate specimen received.

2. Unlabeled specimen or name discrepancy between specimen and request label;

3. Specimen received after prolonged delay (usually more than 72 hours);

4. Specimen received in expired transport container.

Corrective action:

1. Appropriate specimen received.

2. Labeled specimen and no name discrepancy between specimen and request label.

3. Specimen received without delay.

4. Specimen received in valid transport container.

Post analytical errors:

1. Failure in reporting.

2. Erroneous validation of analytical data.

3. Improper data entry.

Corrective action:

1. Write correct report.

2. All analytical data should be valid.

3. Proper data entry.