Cell Count, Amniotic Fluid

CPT: 89051
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Test Details


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


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.1,4,5 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.1,4,6


Microscopic and macroscopic examination

Specimen Requirements


Amniotic, amniocentesis fluid


1 to 2 mL

Minimum Volume

0.5 mL (Note: This volume does not allow for repeat testing.)


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

Patient Preparation

Prior to amniocentesis, an ultrasound examination should be performed.1-3 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


The first 1-2 mL should be discarded due to contamination with blood or maternal cells. When blood-tinged fluid is obtained initially, another syringe should be used to obtain clear fluid, if possible.

Storage Instructions

Refrigerate at 2°C to 8°C; stable 24 hours. Transport to the laboratory as soon as possible.

Causes for Rejection

Room temperature storage; frozen specimen; specimen more than 24 hours old; improperly labeled specimen container

Clinical Information

Special Instructions

Specimens referred to our laboratories for fluid cell counts must be handled properly to ensure accuracy. Please call for handling instructions.


1. Kjeldsberg K, Knight J. Amniotic fluid. Body Fluids. 3rd ed. ASCP Press;1993: 2-4.
2. Klein VR, Cunningham FG. Amniotic fluid: A source for fetal evaluation. Semin Perinatol. 1986 Apr; 10(2):125-135. 3541222
3. Young PE, Wolf DA. Midtrimester amniocentesis. Semin Ultrasound. 1980; 1:311-323.
4. Romero R, Emamian M, Quintero R, et al. The value and limitations of the Gram stain examination in the diagnosis of intraamniotic infection. Am J Obstet Gynecol. 1988 Jul; 159(1):114-119. 2456013
5. Garite TJ, Freeman RK. Chorioamnionitis in the preterm gestation. Obstet Gynecol. 1982 May; 59(5):539-545. 7070724
6. Romero R, Yoon BH, Mazor M, et al. A comparative study of the diagnostic performance of amniotic fluid glucose, white blood cell count, interleukin-6, and Gram stain in the detection of microbial invasion in patients with preterm premature rupture of membranes. Am J Obstet Gynecol. 1993 Oct; 169(4):839-851. 7694463


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
005260 Cell Ct, Amniotic Fluid 005261 Color, Amniotic 38386-9
005260 Cell Ct, Amniotic Fluid 005262 Clarity, Amniotic 9335-1
005260 Cell Ct, Amniotic Fluid 005269 Nucleated Cells, Amniotic /uL 55793-4
005260 Cell Ct, Amniotic Fluid 005265 RBC, Amniotic /uL 55779-3
005260 Cell Ct, Amniotic Fluid 005266 Polys, Amniotic % 26518-1
005260 Cell Ct, Amniotic Fluid 005267 Mononuclear Cells, Amniotic % 26493-7
005260 Cell Ct, Amniotic Fluid 005268 Comments: 20999-9

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