Activated Protein C Resistance (FV:Q506) and Pregnancy
Pelle G. Lindqvist (1) , Peter J. Svensson (2), (4) , Karel Marsÿál (3) , Lars Grennert (1) , Marie Luterkort (5) , Björn Dahlbäck (4)
From the Departments of (1),(3) Obstetrics and Gynecology, (2) Medicine (4) Coagulation Disorders, Lund University, University Hospital, Malmö (1), (2), (4) or Lund (3) , and (5) Slottsstaden Group Practice. Malmö, Sweden
Activated protein C (APC) resistance, due to a point mutation in the
factor V gene (FV:Q506), is a major risk factor for venous thromboembolism.
To determine the prevalence of APC resistance in a large series
of pregnant women, and to elucidate its obstetric consequences, we
performed a prospective study in Malmö, Sweden, comprising 2,480
women enrolled in early pregnancy. The presence of APC resistance
(the FV:Q 506 allele) was determined. The women were interviewed
about their medical histories including venous thromboembolic
events (VTE) in relatives. The outcome variables were the VTE rate,
intrapartum blood loss, and the prevalence of selected pregnancy
complications such as fetal loss, pre-eclampsia, and intrauterine growth
The overall prevalence of APC resistance was 11% (270/2480). The
APC-resistant subgroup did not differ significantly from the non-APC-resistant
subgroup in terms of pregnancy complications, but was
characterized by an 8-fold higher risk of VTE (3/270 vs. 3/2210), a
lower rate of profuse intrapartum haemorrhage (3.7% vs. 7.9%) (p =
0.02), and less intrapartum blood loss (340 ml vs. 361 ml) (p = 0.04).
Despite the high prevalence of APC resistance in this series of gravidae
(11%), its presence was unrelated to adverse pregnancy outcome
apart from an 8-fold increased risk of VTE.