Ann Intern
Med. 1996 Dec 15;125(12):955-60.
Frequency of pregnancy-related venous thromboembolism in anticoagulant
factor-deficient women: implications for prophylaxis.
Friederich PW, Sanson BJ, Simioni P, Zanardi S, Huisman MV, Kindt I,
Prandoni P, Buller HR, Girolami A, Prins MH.
Academic Medical Center, Amsterdam, The Netherlands.
Background:
It has been reported that women with an inherited deficiency of
antithrombin, protein C, or protein S have an increased risk for developing
venous thromboembolic disease during pregnancy and the postpartum period.
However, because the available data on risk are flawed, it is difficult to
define a rational, efficacious, and safe policy about prophylaxis for venous
thromboembolism in these women.
Objectives:
To determine the frequency of
venous thromboembolism during pregnancy and the postpartum period in women
with heritable deficiencies of anticoagulant factors.
Design:
Retrospective
cohort study.
Setting:
University outpatient clinics in the Netherlands and
Italy. PARTICIPANTS: 129 otherwise asymptomatic female family members of
patients with a history of venous thromboembolism and an established
deficiency of antithrombin, protein C, or protein S. MEASUREMENTS: Medical
history, with specific attention to episodes of venous thromboembolism and
obstetric history, was taken. The anticoagulant factor status of the study
participants was determined. If a patient had an episode of venous
thromboembolism, subsequent pregnancies in that patient were not analyzed.
Results:
Of the 129 women who participated in the study, 60 had
anticoagulant factor deficiency and 69 did not. In the nondeficient group,
198 pregnancies occurred; 1 of these (0.5%) was complicated by an episode of
venous thromboembolism during the postpartum period. In the deficient group,
169 pregnancies occurred; 7 of these (4.1%) were complicated by an episode
of venous thromboembolism during the third trimester of pregnancy (2
pregnancies [1.2%]) and the postpartum period (5 pregnancies [3.0%]). The
risk for venous thromboembolism was increased eightfold in deficient women
compared with nondeficient women (hazard ratio, 8.0 [95% CI 1.2 to 184]).
Anticoagulant factor-deficient women have an increased risk for
venous thromboembolism during pregnancy and the postpartum period. Although
data from an appropriate randomized clinical trial are lacking, the
frequency of venous thromboembolism seen in deficient women might justify
the use of anticoagulative prophylaxis during the third trimester of
pregnancy and the postpartum period.
