Altered reference ranges for protein C and protein S during early pregnancy: Implications for the diagnosis of protein C and protein S deficiency during pregnancy

Joanne m. Said; Vera Ignjatovic; Paul T. Monagle; Susan P. Walker; John R. Higgins; Shaun P. Brennecke

doi:10.1160/TH09-07-0476

Thrombosis and Haemostasis, Table of Contents

Thromb Haemost 2010; 103(05): 984-988
DOI: 10.1160/TH09-07-0476

Blood Coagulation, Fibrinolysis and Cellular Haemostasis

Schattauer GmbH

Altered reference ranges for protein C and protein S during early pregnancy: Implications for the diagnosis of protein C and protein S deficiency during pregnancy

Authors

Joanne m. Said

¹Department of Perinatal Medicine, The Royal Women’s Hospital, Parkville, Victoria, Australia

²The University of Melbourne, Department of Obstetrics and Gynaecology, Parkville, Victoria, Australia
Vera Ignjatovic

³Department of Haematology, The Royal Children’s Hospital, Parkville, Victoria, Australia

⁴Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia
Paul T. Monagle

³Department of Haematology, The Royal Children’s Hospital, Parkville, Victoria, Australia

⁴Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia
Susan P. Walker

²The University of Melbourne, Department of Obstetrics and Gynaecology, Parkville, Victoria, Australia

⁵Mercy Hospital for Women, Heidelberg, Victoria, Australia
John R. Higgins

¹Department of Perinatal Medicine, The Royal Women’s Hospital, Parkville, Victoria, Australia

²The University of Melbourne, Department of Obstetrics and Gynaecology, Parkville, Victoria, Australia

⁶Anu Research Centre, Department of Obstetrics & Gynaecology, University College Cork, Ireland
Shaun P. Brennecke

¹Department of Perinatal Medicine, The Royal Women’s Hospital, Parkville, Victoria, Australia

²The University of Melbourne, Department of Obstetrics and Gynaecology, Parkville, Victoria, Australia

Abstract

Summary

Protein S, protein C and antithrombin are important regulators of coagulation. While deficiencies of these proteins have been linked to adverse pregnancy outcomes, testing for these deficiencies during pregnancy is limited by the use of non-pregnant reference ranges and a limited understanding of the changes that occur during pregnancy. Although several small studies have previously reported on the activity of these proteins during pregnancy, potentially important changes have been overlooked by continuing to compare the activity during pregnancy with non-pregnant reference ranges. In the current study, we investigated the activity of protein S, protein C and antithrombin during the first half of pregnancy in 440 otherwise asymptomatic women who went on to have uncomplicated singleton pregnancies. Consistent with previous studies, we found that antithrombin activity remained unchanged, while protein S activity decreased significantly to a mean level of 46%. We did not observe a progressive decrease in protein S during the second trimester as several studies have suggested previously. In contrast, we observed a potentially biologically significant increase in protein C activity throughout the first 22 weeks of pregnancy. Given the physiological role of protein C, we postulate that this increase may play a role in maintaining early pregnancy through both an anticoagulant and an inflammatory regulation pathway.

Keywords

Antithrombin - natural anticoagulants - protein C - protein S - pregnancy - reference ranges - thrombophilia - thrombosis

Full Text

References

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