Treatment of pregnancy-associated venous thromboembolism - position paper from the Working Group in Women’s Health of the Society of Thrombosis and Haemostasis (GTH)

Abstract

Summary: Venous thromboembolism (VTE) is a major cause of maternal morbidity during pregnancy and the postpartum period. However, because there is a lack of adequate study data, management strategies for pregnancy-associated VTE must be deduced from observational studies and extrapolated from recommendations for non-pregnant patients. In this review, the members of the Working Group in Women's Health of the Society of Thrombosis and Haemostasis (GTH) have summarised the evidence that is currently available in the literature to provide a practical approach for treating pregnancy-associated VTE. Because heparins do not cross the placenta, weight-adjusted therapeutic-dose low molecular weight heparin (LMWH) is the anticoagulant treatment of choice in cases of acute VTE during pregnancy. No differences between once and twice daily LMWH dosing regimens have been reported, but twice daily dosing seems to be advisable, at least peripartally. It remains unclear whether determining dose adjustments according to factor Xa activities during pregnancy provides any benefi t. Management of delivery deserves attention and mainly depends on the time interval between the diagnosis of VTE and the expected delivery date. In particular, if VTE manifests at term, delivery should be attended by an experienced multidisciplinary team. In lactating women, an overlapping switch from LMWH to warfarin is possible. Anticoagulation should be continued for at least 6 weeks postpartum or for a minimum period of 3 months. Although recommendations are provided for the treatment of pregnancy-associated VTE, there is an urgent need for well-designed prospective studies that compare different management strategies and defi ne the optimal duration and intensity of anticoagulant treatment. Anticoagulant therapy during pregnancyLow-molecular-weight heparins (LMWH) are considered the anticoagulants of choice in pregnancy-associated VTE because LMWH do not cross the placenta and do not appear at signifi cant levels in breast milk. Although a Cochrane Review stated that there was no evidence from randomised controlled trials regarding the effi cacy of anticoagulant therapy for DVT in pregnancy [2], two systemic reviews of LMWH use in pregnant women have confi rmed their efficacy and safety, which were consistent with those in nonpregnant women [3,4]. Compared to unfractionated heparin (UFH), LMWH were associated with a substantially lower risk of adverse side eff ects, such as heparin-induced thrombocytopenia (HIT), haemorrhage, and osteoporosis [3 -7]. However, UFH may be considered an alternative if LMWH cannot be used or if UFH seems to be advantageous over LMWH, e.g., in women at high risk of bleeding complications or in women with severe renal impairment. Women with confi rmed PE and haemodynamic compromise who are candidates for subsequent thrombolysis should also receive UFH during the initial phase until defi nitive treatment decisions are reached [1]. Data obtained from non-pregnant patients have confi rmed that LMWH are at least as eff ective...

Vein Thrombosis Risk in Women and Travel

“…In passengers, with a BMI over 30, the risk of VTE is increased even by sixfold. Significant differences regarding the risk of thrombosis (measurement of the D-dimers) between the first/business class and the economy class have not yet been demonstrated; however, related data are limited [26][27][28][29].…”

“…This provides the basis for risk-adapted thromboembolism prophylaxis. A total of five guidelines make riskrelated recommendations including risk classification for VTE after air travel [26][27][28][29].…”

“…With intermediate risk, e.g., pregnancy/puerperium, in addition to the general measures from a flight duration of 4 h, the wearing of graduated compression stockings up to the knee is recommended. The importance of compression stockings for thrombosis prophylaxis on long-haul flights (>4 h) also emerges from a 2006 Cochrane analysis (revised 2010) including 10 randomized trials [26][27][28][29][30][31][32][33].…”

Pulmonary Complications of Pregnancy: Venous Thromboembolism

“…This is in contrast to some of the published guidelines that recommend CTPA for patients with an abnormal chest X-ray. 59,[69][70][71] Bilateral leg ultrasound imaging is an alternative first-line imaging strategy in a pregnant patient with suspected PE, with the main advantage of avoiding radiation exposure if a DVT is diagnosed. This strategy is low yield and is not costeffective if a patient has no leg symptoms; in a retrospective study of 158 pregnant women with suspected PE, no DVT was detected in 136 patients without leg symptoms, compared with 1 DVT diagnosed among 20 patients with leg symptoms.…”

Therapeutic heparin during the peripartum period

“…Following CS a trend to the use of UFH over LMWH was observed. Reversibility featured prominently as a cited reason for this choice given the increased risk of PPH and wound complications post CS compared with SVD (127). Delayed primary and secondary post-partum bleeding is a frequent complication in women who require therapeutic levels of anticoagulation in the postnatal peripartum period (100).…”