Thromb Haemost 2010; 103(04): 718-727
DOI: 10.1160/TH09-10-0704
Blood Coagulation, Fibrinolysis and Cellular Haemostasis
Schattauer GmbH

Haemostatic reference intervals in pregnancy

Pal B. Szecsi
1  Department of Clinical Biochemistry, Gentofte Hospital, University of Copenhagen, Denmark
,
Maja Jørgensen
2  The Thrombosis Center, Gentofte Hospital, University of Copenhagen, Denmark
,
Anna Klajnbard
3  Department of Obstetrics and Gynecology, Gentofte Hospital, University of Copenhagen, Denmark
,
Malene R. Andersen
1  Department of Clinical Biochemistry, Gentofte Hospital, University of Copenhagen, Denmark
,
Nina P. Colov
3  Department of Obstetrics and Gynecology, Gentofte Hospital, University of Copenhagen, Denmark
,
Steen Stender
1  Department of Clinical Biochemistry, Gentofte Hospital, University of Copenhagen, Denmark
› Author Affiliations
Financial support: Diagnostica Stago, Asnieres Sur Seine, France donated the reagents used in this study.
Further Information

Publication History

Received: 15 October 2009

Accepted after major revision: 10 February 2009

Publication Date:
22 November 2017 (online)

Summary

Haemostatic reference intervals are generally based on samples from non-pregnant women. Thus, they may not be relevant to pregnant women, a problem that may hinder accurate diagnosis and treatment of haemostatic disorders during pregnancy. In this study, we establish gestational age-specific reference intervals for coagulation tests during normal pregnancy. Eight hundred one women with expected normal pregnancies were included in the study. Of these women, 391 had no complications during pregnancy, vaginal delivery, or postpartum period. Plasma samples were obtained at gestational weeks 13–20, 21–28, 29–34, 35–42, at active labor, and on postpartum days 1 and 2. Reference intervals for each gestational period using only the uncomplicated pregnancies were calculated in all 391 women for activated partial thromboplastin time (aPTT), fibrinogen, fibrin D-dimer, antithrombin, free protein S, and protein C and in a subgroup of 186 women in addition for prothrombin time (PT), Owren and Quick PT, protein S activity, and total protein S and coagulation factors II, V, VII, VIII, IX, X, XI, and XII. The level of coagulation factors II, V, X, XI, XII and antithrombin, protein C, aPTT, PT remained largely unchanged during pregnancy, delivery, and postpartum and were within non-pregnant reference intervals. However, levels of fibrinogen, D-dimer, and coagulation factors VII, VIII, and IX increased markedly. Protein S activity decreased substantially, while free protein S decreased slightly and total protein S was stable. Gestational age-specific reference values are essential for the accurate interpretation of a subset of haemostatic tests during pregnancy, delivery, and puerperium.