Activated partial thromboplastin time , aPTT (whole blood)
Units
Nonpregnant Adult
First Trimester
Second Trimester
Third Trimester
Seconds
26.3
- 39.4
24.3
- 38.9
24.2
- 38.1
24.7
- 35.0
Causes of a prolonged aPTT include, but are not limited to, heparin, coumadin, lupus anticoagulant, coagulation factor deficiencies , and
specific coagulation factor inhibitors
References:
Abbassi-Ghanavati M, Greer LG, Cunningham FG. Pregnancy and laboratory
studies: a reference table for clinicians. Obstet Gynecol. 2009
Dec;114(6):1326-31. PMID:19935037
Wallach, J. Interpretation
of Diagnostic Tests, Eighth ed. Lippincott Williams & Wilkins, 2007 Fischbach FT, Dunning MB III, eds.
A Manual of Laboratory and Diagnostic Tests, 7th ed. Philadelphia,
Lippincott Williams and Wilkins,2004
