Antithrombin III activity in healthy pregnant women seen at the University of Benin Teaching Hospital, Benin City

Abstract

Background: Antithrombin (AT III) is a glycoprotein synthesized by the liver. It has anticoagulant and antiinflammatory properties. Pregnancy is a hypercoagulable state due to increased synthesis of coagulation protein and depletion in the activity of natural anticoagulant due to consumption by activated coagulation proteins. Varying AT III activities have been reported in normal pregnancy but this has not been investigated in our environment.

Objective: This study aims to determine antithrombin (AT III) levels in normal pregnancy, to compare changes in second and third trimester and to correlate AT III levels with gestational age and haematological parameters.

Methods: This is a cross sectional study conducted at the University of Benin Teaching Hospital, Benin City. Eighty apparent normal pregnant women recruited at the antenatal clinic were evaluated for AT III activity using Technoclone chromogenic AT III kit and haematological parameters using automated Hematology Analyzer, ERMA INC (Tokyo model FCE 2.0). The data was analyzed using SPSS version 16.

Result: The average age of the women was 31.2 ± 4.3years at a mean gestational age of 28.1±5.5 weeks. Their mean haematocrit, white blood cell count, platelet counts and AT III activity were 33.6 ± 3.6%, 6.5 ± 2.0 x 10⁹ /L, 193.3 ± 48.7 x 10⁹ /L and 82.2±30.2% respectively. AT activity was significantly reduced in the third trimester (p = 0.005). A negative correlation coefficient was found between AT III activity and gestational age (r = -0.337; p = 0.003).

Conclusion: The mean AT III levels is within normal range in pregnancy however there is a significant decline in activity in the third trimester.

Keywords: Antithrombin III activity, Haematological parameters, Healthy Pregnancy, Benin City