Women with History of VTE at increased risk of VTE during pregnancy
Venous thromboembolism (VTE), specifically pulmonary embolism (PE) resulting from deep venous thrombosis (DVT), is one of the leading causes of maternal death in the developed world. A recent study reiterates that the risk of recurrent VTE postpartum is high among women with a history of previous VTE despite the use of thromboprophylaxis. The study findings were published in the journal of thrombosis and haemostasis on 12 January 2022.
The risk of pregnancy-associated VTE is up to 6 times that of the general population, with an absolute risk of up to 12.2 per 10,000, compared with 2 per 10,000 in nonpregnant women. To further explore Dr Claire de Moreuil and his team conducted a study and assessed the incidence rate of recurrent VTE during pregnancy, according to the period of pregnancy and the clinical parameters associated with recurrence in women of childbearing age after a first VTE.
In a prospective cohort study, the researchers included 189 women with a first documented VTE and followed them until a subsequent pregnancy of at least 20 weeks gestation between 2000 and 2020. They evaluated the VTE recurrences during pregnancy and potential clinical risk factors for recurrence.
Key findings of the study:
♦ Upon analysis, the researchers observed that recurrent VTE occurred in six women during antepartum:
- Five during the first trimester (incidence rate 106.4 per 1000 women-years);
- None during the second trimester; and
- One during the third trimester (incidence rate 27.0 per 1000 women-years).
♦ During postpartum, they noted that recurrences occurred in 11 women (incidence rate 212.8 per 1000 women-years).
♦ They further noted that these 17 recurrent VTEs presented as pulmonary embolism ± deep vein thrombosis (DVT) in five patients and isolated DVT in 12.
♦ They observed failure of thromboprophylaxis in two cases (33.3%) antepartum and in 10 cases (90.9%) postpartum.
♦ Upon multivariable analysis, they noted only obesity (defined on prepregnancy body mass index) was associated with recurrent VTE (odds ratio 3.34).
The authors concluded, "This study confirms a high risk of recurrent VTE postpartum, despite thromboprophylaxis, in women with a previous VTE. Only obesity was associated with VTE recurrence during pregnancy, suggesting that low-dose anticoagulation might not be appropriate in obese pregnant women."
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