Pregnancy loss and thrombosis with protein C deficiency.

OBJECTIVES

Protein C inhibits coagulation and promotes fibrinolysis. This study investigates the association between protein C deficiency and pregnancy loss, thrombosis in pregnancy, and thrombosis with oral contraception.

STUDY

DESIGN

Fifteen protein C--deficient patients and 37 controls from a single kindred were studied. An obstetric history was obtained by telephone. Data were analyzed by logistic regression, Fisher's exact test, and Student t test.

RESULTS

Protein C--deficient women experienced a 33% pregnancy loss versus 19% in the controls (not significant). Thromboembolism during pregnancy in protein C--deficient women was 33% (45% in those not receiving prophylactic anticoagulation) versus 5% in controls (odds ratio 7.37, p = 0.026). Five of 12 protein C--deficient women using oral contraception developed thrombosis versus 0 of 33 controls. The risk of thrombosis for protein C--deficient women using oral contraception is increased (p < 0.001).

CONCLUSIONS

Perinatal outcome is not statistically different with protein C deficiency. Protein C deficiency increases the risk of thrombosis during pregnancy and with oral contraception. Prophylactic heparin is suggested during pregnancy for protein C--deficient women with personal or family histories of thrombosis. Oral contraception is not advised.