Q: All of the following are causes of Antithrombin (AT) deficiency except?

A)  Liver cirrhosis
B) Nephrotic syndromes 
C) Extracorporeal membrane oxygenation (ECMO) 
D) Hemodialysis 
E) Normal pregnancy


Answer: E

Objective of above question is to highlight the fact that patients on ECMO and HD may have lower AT deficiency. This may be related to cannula itself. As these patients, while in ICU frequently requires heparin, deficiency of AT may cause ineffective anticoagulation. In such scenarios administration of AT may be required. Normal pregnancy does not cause any AT deficiency but may be present in preeclampsia or eclampsia.

Cirrhosis and Nephrotic syndrome are understandably the causes of AT deficiency.  


References:

1. Alegre A, Vicente V, Gonzalez R, Alberca I. Effect of hemodialysis on protein C levels. Nephron 1987; 46:386. 

2. Weenink GH, Treffers PE, Vijn P, et al. Antithrombin III levels in preeclampsia correlate with maternal and fetal morbidity. Am J Obstet Gynecol 1984; 148:1092.