Page 2344 - Hematology_ Basic Principles and Practice ( PDFDrive )

2086 Part XII Hemostasis and Thrombosis

TABLE Management of Women With a History of Venous Thrombosis During Pregnancy and the Puerperium
140.6
Clinical History Thrombophilia Antepartum Postpartum a
Prior VTE due to a transient No Surveillance Yes
risk factor
Prior VTE due to pregnancy Yes or no Prophylactic LMWH Yes
or estrogens
Prior idiopathic VTE Yes or no Prophylactic LMWH Yes
Recurrent VTE Yes or no Treatment dose LMWH Resume long-term anticoagulation
No prior VTE Antithrombin deficiency; homozygous Prophylactic or intermediate Yes
Positive family history FII G20210A; or Factor V Leiden ; or dose LMWH
dual heterozygosity for both mutations
a Postpartum prophylaxis involves a 6-week course of prophylactic doses of LMWH or dose-adjusted warfarin (target INR: 2.0 to 3.0).
LMWH, low-molecular-weight heparin; VTE, venous thromboembolism.

parenteral administration, although the drug has been shown to be anticoagulation for pregnancy-related venous thrombosis. In total,
cost-effective in patients at high risk for recurrent venous treatment should be given for 3 to 6 months from the time of diag-
thromboembolism. nosis. Warfarin and LMWH can be safely administered in nursing
mothers, with no detectable anticoagulant effect in breast milk.
Women with a past history of unprovoked or recurrent venous
Duration of Treatment thromboembolism, those homozygous for factor V Leiden or the
FII G20210A mutation, and those with deficiencies of antithrombin,
The presence of a hypercoagulable state has no influence on the protein C, or protein S and a family history of venous thrombosis,
duration of anticoagulant treatment in patients whose venous throm- should receive antepartum prophylaxis with LMWH. Postpartum,
boembolic event occurred in the setting of a well-recognized and LMWH or warfarin should be given for 6 weeks. Postpartum treat-
transient risk factor, such as major surgery or prolonged immobiliza- ment with LMWH or warfarin for 6 weeks is likely adequate for
tion due to medical illness. These patients are treated with anticoagu- women with a history of venous thrombosis secondary to a well-
lants for at least 3 months. For those with unprovoked venous defined risk factor. Prophylaxis during pregnancy, as well as postpar-
thromboembolism, a minimum of 3 months of anticoagulation tum, should be considered for women who developed venous
treatment is recommended at which point individualized assessment thromboembolism after taking oral contraceptives particularly if they
of the risk of recurrence without anticoagulation and the risk of have underlying thrombophilia. Women with thrombophilic defects,
bleeding with anticoagulation should be undertaken. Unless the risk but no prior history of venous thromboembolism, or family history
of bleeding is high, most patients should receive extended anticoagu- of the same likely do not require antepartum prophylaxis or postpar-
lation therapy. Heterozygosity for factor V Leiden or the FIIG20210A tum treatment, but definitive data are lacking. A summary of these
mutation does not influence the risk for recurrence. In contrast, recommendations is provided in Table 140.6. 30
patients with deficiency of antithrombin, protein C, or protein S or
those homozygous for factor V Leiden or the FII G20210A mutation
appear to be at higher risk for recurrence and likely should receive Thrombophilia and Fetal Loss
longer-term anticoagulation treatment. Likewise, patients with APS
with a persistent ACL or LA are also at high risk for recurrence and About 30% of women have at least one fetal loss, and approximately
require long-term treatment. 5% of women of reproductive age experience recurrent fetal loss.
The decision to continue anticoagulation indefinitely requires Women with hereditary or acquired thrombophilia have a two- to
consideration of the site and severity of the first episode of venous five-fold increased risk for fetal loss. Screening for APS is recom-
thromboembolism, information on whether or not the event was mended if there is a history of three or more miscarriages before 10
provoked, assessment of the risk for anticoagulant-related bleeding weeks’ gestation. Although once-daily LMWH in prophylactic doses,
and other risk factors such as an elevated D-dimer level after stopping with or without aspirin, is often prescribed for women with recur-
25
anticoagulant therapy. The decision should also take into account rent fetal loss on the background of an underlying thrombophilic
patient adherence and patient preferences. defect, such therapy is of no benefit and it is costly and potentially
harmful.
Treatment and Prevention of Thrombosis
During Pregnancy CONCLUSIONS AND FUTURE DIRECTIONS

Thrombophilic disorders have no influence on the treatment of Inherited or acquired hypercoagulable states can now be identified in
venous thrombosis during pregnancy. Due to its better bioavailability up to 50% of patients with venous thromboembolism thanks to an
and longer half-life, LMWH is preferred over subcutaneous heparin; increased understanding of the regulation of coagulation. The role of
fondaparinux is reserved for women with an allergy to heparin. these disorders in the pathogenesis of arterial thrombosis is less clear,
LMWH can be given once or twice daily in a weight-adjusted fashion. and further research is necessary to identify those individuals vulner-
The need for dose adjustments and monitoring during the course of able to arterial thrombosis after plaque rupture. Despite an improved
pregnancy remains controversial. The non–vitamin K antagonist oral ability to diagnose hypercoagulable states, the impact of this informa-
anticoagulants should not be used in pregnancy or in nursing mothers tion on clinical decisions remains limited. Common congenital
because these drugs have the potential to cross the placenta and it is hypercoagulable states increase the risk for a first thrombotic episode
unknown whether they pass into breast milk. but appear to have little impact on the risk for recurrence. Identifica-
After delivery, LMWH or warfarin should be given for at tion of biomarkers for patients at risk for recurrent thrombosis and
least 6 weeks. No studies have addressed the optimal duration of elucidating new hypercoagulable states are goals for the future.