Interpretation of Amniotic Fluid White Blood Cell Count in “Bloody Tap” Amniocenteses in Women With Symptoms of Preterm Labor

. Author manuscript; available in PMC: 2014 Aug 25.

Published in final edited form as: Obstet Gynecol. 2010 Aug;116(2 0 1):344–354. doi: 10.1097/AOG.0b013e3181e8fec6

Amniotic fluid:
WBC count: 200 cells/mm³
RBC count: 78,500 cells/mm³
glucose 40 mg/dL
LDH: unable to measure
Gram stain: negative

Predicted

WBC count = 78,500 \times \frac{9,200 \times 94}{36.1 \times 10^{7}} = 188 {cells / mm}^{3}

Corrected WBC count = 200 − 188 = 12 cells/mm³

Corrected WBC count (rapid subtraction) = 200 − 190 = 10 cells/mm³

Maternal hematology:
WBC count: 9,200 cells/mm³
Hematocrit: 36.1%
MCV: 94 fL