Thromb Haemost 1998; 79(06): 1166-1170
DOI: 10.1055/s-0037-1615035
Rapid Communication
Schattauer GmbH

Activated Protein C Sensitivity, Protein C, Protein S and Coagulation in Normal Pregnancy

P. Clark
1   From the Department of Haematology, Royal Infirmary, Glasgow, UK
,
J. Brennand
2   University Department of Obstetrics and Gynaecology, Royal Infirmary, Glasgow, UK
,
J. A. Conkie
1   From the Department of Haematology, Royal Infirmary, Glasgow, UK
,
F. McCall
1   From the Department of Haematology, Royal Infirmary, Glasgow, UK
,
I. A. Greer
2   University Department of Obstetrics and Gynaecology, Royal Infirmary, Glasgow, UK
,
Isobel D. Walker
1   From the Department of Haematology, Royal Infirmary, Glasgow, UK
› Author Affiliations
Further Information

Publication History

Received 29 July 1997

Accepted after resubmission 26 February 1998

Publication Date:
07 December 2017 (online)

Summary

A prospective study of activated protein C sensitivity, protein C, protein S, and other coagulation factors in 239 women during normal pregnancy was carried out. Protein C activity appeared unaffected by gestation, although an elevation of protein C activity was observed in the early puerperium. A fall in total and free protein S with increasing gestation was observed. Activated protein C sensitivity ratio (APC:SR) showed a progressive fall through pregnancy. This fall correlated with changes in factor VIIIc, factor Vc and protein S. 38% of subjects, with no evidence of Factor V Leiden or anticardiolipin antibodies, showed a low APC:SR (APC:SR <2.6) in the third trimester of pregnancy. Aside from a significant reduction in birth weight, no difference in pregnancy outcome was observed between these subjects and those with a normal APC:SR. Activated protein C sensitivity ratio, modified by pre-dilution of patient samples with factor V depleted plasma, showed no consistent trend with gestation.