Pregnancy Complicated by Venous Thrombosis

Pregnant women are at 5 times higher risk of venous thromboembolism (VTE), a leading cause of maternal morbidity and mortality, than nonpregnant women. In pregnant women, it more often occurs in the left leg at a proximal rather than distal region and is associated with increased embolic complication and postthrombotic syndrome. Risk factors include hyperemesis, high body mass index, immobility, and thrombophilias. It is often difficult to diagnose; symptoms such as leg swelling and dyspnea (common in pregnancy) are only suggestive, and chest radiographic findings are usually normal as features of pulmonary embolism and ventricular strain are often nonspecific (eg, atelectasis, tachycardia, and right ventricular strain). Multiple studies have recommended compression duplex ultrasonographic examination and ventilation-perfusion lung scanning as effective first-line diagnosis methods, but magnetic resonance imaging, conventional x-ray venography, and computed tomographic pulmonary angiography can also be used in cases of abnormal chest radiography or indeterminate first-line findings. Other pretest assessments include the “LEFT” rule (left calf circumference ≥2 cm than right calf, edema, first-trimester presentation), the Wells score, and D-dimer testing, but the usefulness of these assessment is uncertain/yet to be confirmed. Treatments are low-molecular-weight heparins except for during the 24-hour period before labor and 4 hours after anesthesia end. Unfractionated heparin and coumadin can be used in breast-feeding mothers, fondaparinux use and caval filters are being debated, and oral direct thrombin inhibitors should be avoided. Using these guidelines, the author of the study describes a case of women older than 35 years with high body mass index and immobility and dehydration associated with morning sickness. Complex duplex ultrasonography suggests VTE, and the author recommends prompt treatment with low-molecular-weight heparin throughout the peripartum period, pausing treatment during the delivery period.