Venous thromboembolism during pregnancy: Trends, incidence, and risk patterns in a large cohort population

Abstract

Venous thromboembolism (VTE), which includes deep venous thrombosis (DVT) and pulmonary embolism, are among the leading causes of maternal morbidity and mortality, with an incidence of approximately 0.48-1.1 per 100 000 deliveries. [1][2][3] Pregnancy and the puerperium are well-established risk factors for VTE. [4][5][6] It is accepted that there is a 5-to 10-fold increased risk of thrombus formation during pregnancy and the postpartum period, 5-7 with an incidence of VTE in the range of 0.5-2 per 1000 pregnancies. [8][9][10] While the postnatal period is commonly considered to have the highest incidence of VTE, 11 some studies reported a higher antenatal incidence 8 or no difference. 12 In addition, some studies have suggested that the incidence appears to be decreasing over the last four decades, largely due to a decrease of events in the postpartum period. 8,13

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“…The rise in maternal hormones and circulating procoagulant substances results in a reduction in thrombin time, prothrombin time, activated partial thromboplastin time & INR [3] . In pregnant women with prosthetic mechanical valves, thromboembolism rates ranged from 7 -23 % per patient per year [4,5] . Despite recommendations that VKA should be the first-line antepartum therapy, low-molecularweight heparin (LMWH) is a significantly less effective anticoagulant, and various research indicate that the risk of embryopathy is low roughly 1 -2 % when the mother is on warfarin at 5 mg per day or less [6] .…”

“…Recent recommendations classify warfarin as class I during the 2 nd & 3 rd trimesters, as the warfarin embryopathy risk is limited to weeks 6 to 12. During the 1 st trimester, warfarin doses of 5 7), [1][2][3][4][5][6] as class IIa, making it superior to unfractionated or LMWH [7,8] . Patients with mechanical heart valves have an elevated risk of maternal morbidity and mortality after delivery.…”

Postpartum Outcomes in Patients Receiving Venous Thromboembolism Prophylaxis during Antepartum Admission

“…6,7 While focus has been placed on thromboprophylaxis, there continues to be a persistently elevated incidence of thromboembolism events in pregnancy over the last decades. 8,9 As such, multiple societies, such as the American College of Obstetricians and Gynecologists (ACOG), Society for Maternal-Fetal Medicine (SMFM), Royal College of Obstetricians and Gynecologists (RCOG), and the American College of Chest Physicians (ACCP) have recommended risk-stratified methods for determination of eligibility criteria for heparinbased chemoprophylaxis during pregnancy and the PP period. [10][11][12][13] Our institution adopted a risk-stratified strategy for heparin-based VTE prophylaxis in 2016, adapted from the ACOG District II Safe Motherhood Initiative VTE Bundle.…”

Incidence and Risk Factors for Pregnancy-Associated Venous Thromboembolism: Are There Differences between East and West?

“…14 Reported risk factors for PA-VTE included multiparity, multifetal pregnancies, advancing maternal age, cesarean section, cardiac disease, delivery at gestational age of <36 weeks, a body mass index of 25, or more, and postpartum period. [15][16][17] These risk factors were not obviously different between Western and Eastern population (►Fig. 1).…”