Venous thromboembolism in pregnancy and postpartum: Treatment

INTRODUCTION — Lower extremity deep vein thrombosis (DVT) and pulmonary embolism (PE) are collectively referred to as venous thromboembolism (VTE). Pregnancy and the postpartum period are well-established risk factors for VTE.

This topic will discuss treatment options for VTE in pregnant and postpartum patients, which differ from those associated with treatment of nonpregnant patients in several ways [1-6]. The suggestions in this topic are based on the assumption that a radiologic diagnosis of DVT and/or PE has been made. Our approach is generally consistent with the guidelines on management of VTE in pregnancy published by the American College of Chest Physicians (ACCP), American College of Obstetricians and Gynecologists (ACOG), European Society of Cardiology (ESC), European Respiratory Society (ERS), and American Society of Hematology (ASH) [1,7-10].

The epidemiology, pathogenesis, diagnosis, and prevention of VTE during pregnancy and the postpartum period are discussed separately:

●(See "Deep vein thrombosis in pregnancy: Epidemiology, pathogenesis, and diagnosis".)

●(See "Pulmonary embolism in pregnancy: Clinical presentation and diagnosis".)

●(See "Venous thromboembolism in pregnancy: Prevention".)

Other VTE-related issues in nonpregnant individuals are also discussed separately:

●(See "Clinical presentation and diagnosis of the nonpregnant adult with suspected deep vein thrombosis of the lower extremity".)

●(See "Clinical presentation, evaluation, and diagnosis of the nonpregnant adult with suspected acute pulmonary embolism".)

●(See "Overview of the treatment of proximal and distal lower extremity deep vein thrombosis (DVT)".)

●(See "Treatment, prognosis, and follow-up of acute pulmonary embolism in adults".)

●(See "Venous thromboembolism: Initiation of anticoagulation" and "Venous thromboembolism: Anticoagulation after initial management".)

GENERAL PRINCIPLES OF TREATMENT — We endorse a multidisciplinary approach using similar indications as in the nonpregnant population.

Indications — We consider the following approach as reasonable during pregnancy and the postpartum period:

Proximal DVT and symptomatic PE — Indications for treating pregnant and postpartum patients with proximal DVT and/or symptomatic PE are generally similar to the nonpregnant population (algorithm 1), the details of which are found separately. (See "Overview of the treatment of proximal and distal lower extremity deep vein thrombosis (DVT)", section on 'Indications' and "Treatment, prognosis, and follow-up of acute pulmonary embolism in adults", section on 'Our approach'.)

Distal DVT and small subsegmental PE — During pregnancy, the optimal treatment of distal DVT (ie, calf vein DVT) and incidental or small subsegmental PE (SSPE) is unknown. Our approach for most patients with distal DVT or SSPE is treatment with anticoagulation, although there may be rare exceptions (eg, very small perforator vein clot and normal D-dimer level, suspected artifact on computed tomographic pulmonary angiography). Further details regarding indications for management of distal DVT and SSPE in nonpregnant patients are provided separately. (See "Overview of the treatment of proximal and distal lower extremity deep vein thrombosis (DVT)", section on 'Distal DVT' and "Treatment, prognosis, and follow-up of acute pulmonary embolism in adults", section on 'Patients with subsegmental PE'.)

Empiric therapy — Principles of empiric therapy are similar to those in nonpregnant individuals. (See "Clinical presentation and diagnosis of the nonpregnant adult with suspected deep vein thrombosis of the lower extremity", section on 'Empiric anticoagulation' and "Treatment, prognosis, and follow-up of acute pulmonary embolism in adults", section on 'Empiric anticoagulation'.)

Multidisciplinary team — When managing patients with venous thromboembolism (VTE) during pregnancy and the postpartum period, we advocate for a multidisciplinary approach (eg, PE response team, pulmonology, maternal-fetal medicine, obstetric anesthesia, hematology, neonatology). This is particularly important for those with complex VTE or life-threatening symptoms, in whom the choice of treatment is influenced by specific clinical factors, such as stage of pregnancy and proximity to delivery. The value of multidisciplinary teams in the management of life-threatening PE in nonpregnant individuals is discussed in detail separately. (See "Treatment, prognosis, and follow-up of acute pulmonary embolism in adults", section on 'Pulmonary embolism response teams (PERT)'.)

NON-LIFE-THREATENING THROMBOSIS

Assess bleeding risk — Since anticoagulation is the cornerstone of therapy, we assess the bleeding risk in all patients who develop venous thromboembolism (VTE) during pregnancy or the postpartum period. The de novo risk of bleeding in most pregnant patients is low. However, the consequences associated with bleeding in patients who develop specific obstetric complications can lead to potentially devastating outcomes, thereby increasing this risk for pregnant patients in general.

●General bleeding risk – As with nonpregnant patients, we categorize pregnant individuals as low risk (ie, three-month bleeding risk <2 percent) or high-risk (ie, bleeding risk >13 percent) based on a number of risk factors (eg, age, platelet count, comorbidities) (table 1). For patients with a bleeding risk between these values (moderate risk), the optimal management must be individualized according to the values and preferences of the patient as well as the risk-benefit ratio, which may change over time. (See "Overview of the treatment of proximal and distal lower extremity deep vein thrombosis (DVT)", section on 'Assessing bleeding risk' and "Venous thromboembolism: Anticoagulation after initial management", section on 'Risk of bleeding'.)

●Obstetric-specific risk – Unique to pregnancy are the risks of antepartum placental abruption (with both consumptive and dilutional disseminated coagulopathy) and postpartum hemorrhage, both of which can have catastrophic consequences (eg, maternal disseminated intravascular coagulation, hypovolemic shock, death; fetal distress, fetal growth restriction, fetal and neonatal death). The frequency of these outcomes as a result of therapeutic anticoagulation is poorly quantified. Risk factors and consequences for these conditions are discussed separately. (See "Acute placental abruption: Pathophysiology, clinical features, diagnosis, and consequences" and "Overview of postpartum hemorrhage".)

Most patients: Anticoagulation — Similar to nonpregnant patients, anticoagulation is the mainstay of therapy for VTE in pregnant and postpartum patients, provided there is no contraindication. However, agent selection and duration of anticoagulant therapy differs from the nonpregnant population [1].

During pregnancy, labor and delivery, and postpartum — Anticoagulation differs between the different stages of pregnancy and the postpartum period.

●During pregnancy – Agent choice and efficacy data that support anticoagulants in pregnant patients with VTE are similar to pregnant patients with other indications for anticoagulant therapy (table 2).

In brief, the following applies:

•For most pregnant patients, subcutaneous low molecular weight (LMW) heparin is the agent of choice (table 2). LMW heparin may be switched to unfractionated heparin (UFH) in some patients prior to labor.

•Warfarin and direct oral anticoagulants (DOACs) are typically avoided in pregnancy.

The rationale for agent choice as well as suitable agents for patients with acute renal failure, patients who need rapid short-term control of anticoagulation, and alternatives to heparin are discussed in detail elsewhere. (See "Use of anticoagulants during pregnancy and postpartum", section on 'Choice of anticoagulant'.)

●Labor and delivery – We generally avoid anticoagulation during labor and delivery. In rare cases of VTE, when even a short interval without anticoagulant therapy is undesirable (eg, hemodynamically significant PE within previous two to four weeks, poor cardiopulmonary reserve), either delivery can proceed despite full anticoagulation or a temporary inferior vena cava (IVC) filter can be inserted and anticoagulation discontinued [11]. Choosing among these options should be decided on a case-by-case basis with a multidisciplinary team approach and shared decision making with the patient. Management of anticoagulation during labor and delivery and role of an IVC filter are provided separately. (See "Use of anticoagulants during pregnancy and postpartum", section on 'Labor and delivery' and 'IVC filter predelivery' below.)

If labor begins unexpectedly, delivery on full anticoagulation is feasible; many patients who deliver while anticoagulated do not have excessive intrapartum bleeding or require a reversal agent [11]. However, neuraxial anesthesia should not be administered to such patients due to the risk of spinal or epidural hematoma [12,13]. This is discussed in detail separately. (See "Use of anticoagulants during pregnancy and postpartum", section on 'Neuraxial anesthesia' and "Adverse effects of neuraxial analgesia and anesthesia for obstetrics", section on 'Neuraxial analgesia and the anticoagulated patient'.)

●Postpartum and lactation – Agent choice in the postpartum period depends on patient preferences, desire for lactation, complications that may have occurred during labor and delivery (eg, postpartum hemorrhage, traumatic neuraxial catheter placement) or complications that may require further intervention (eg, potential dilation and curettage for retained placental products).

•For most patients in whom lactation is desired and no procedure is anticipated, LMW heparin is our initial agent of choice after delivery. We continue LMW heparin through the postpartum period or transition to warfarin if desired by the patient. For patients in whom a potential procedure is anticipated, intravenous UFH is the usual alternative. DOACs are avoided during breast feeding [14].

•For patients in whom lactation is not desired, LMW heparin, UFH, warfarin, or a DOAC is appropriate. Our preference is to use a DOAC, although data to support DOACs in this setting are indirect and derived from the nonpregnant population. (See "Venous thromboembolism: Anticoagulation after initial management", section on 'Direct thrombin and factor Xa inhibitors'.)

Anticoagulation in postpartum patients and those who are lactating is discussed in detail separately. (See "Use of anticoagulants during pregnancy and postpartum", section on 'Postpartum and breastfeeding'.)

Duration of therapy — For patients with VTE during pregnancy or the postpartum period, the optimal duration of anticoagulation is unknown and should be individualized on a case-by-case basis.

Our approach is based on extrapolated data from the nonpregnant population, the known high risk of VTE during pregnancy and the first six weeks postpartum, as well as our clinical experience [1,15-18]. As examples:

●For those with VTE diagnosed during pregnancy, we treat with anticoagulant therapy for at least three months; this duration should include the remainder of pregnancy and at least six weeks postpartum.

●For those with VTE diagnosed postpartum, we treat with anticoagulation for a minimum of three months.

●Once the finite period of anticoagulant therapy is completed, we evaluate patients for possible continued or indefinite therapy (eg, persistent risk factors). We follow the same general principles as in the nonpregnant population. (See "Selecting adult patients with lower extremity deep venous thrombosis and pulmonary embolism for indefinite anticoagulation".)

Outpatient anticoagulation — Some patients with VTE may have anticoagulant therapy initiated solely as an outpatient. Such patients must be carefully selected and meet the same selection criteria as nonpregnant patients. This is discussed in detail separately. (See "Overview of the treatment of proximal and distal lower extremity deep vein thrombosis (DVT)", section on 'Outpatient versus inpatient therapy' and "Treatment, prognosis, and follow-up of acute pulmonary embolism in adults", section on 'Outpatient anticoagulation'.)

When outpatient anticoagulation therapy is selected, we typically use LMW heparin since DOACs are avoided during pregnancy and breastfeeding. (See 'During pregnancy, labor and delivery, and postpartum' above.)

Only limited data support outpatient therapy in pregnant patients. In one observational study including 126 patients with VTE, 16 of whom were treated as an outpatient, none had VTE recurrence or death [19].

IVC filter predelivery — For pregnant patients with VTE who are at low bleeding risk, we do not routinely place an IVC filter. The vast majority of patients who need an IVC filter are those with contraindication to anticoagulation, the details of which are discussed below. (see 'Patients at high bleeding risk or contraindications to anticoagulation: IVC filter' below)

Infrequently, however, we sometimes concurrently place an IVC filter when the pulmonary vascular bed is already significantly compromised and unlikely to tolerate another insult (eg, large PE, chronic thromboembolic pulmonary hypertension, significant underlying lung disease) or when bleeding is anticipated and the risk of stopping anticoagulation, even for a short period, is undesirable (eg, hemodynamically significant PE within previous two to four weeks). (See 'During pregnancy, labor and delivery, and postpartum' above and 'Patients at high bleeding risk or contraindications to anticoagulation: IVC filter' below.)

Patients at high bleeding risk or contraindications to anticoagulation: IVC filter — Similar to the nonpregnant population, for those in whom anticoagulation is contraindicated or the bleeding risk is too high for the administration of anticoagulant therapy, options are limited to the placement of an IVC filter. For such patients, we place a suprarenal, temporary, retrievable IVC filter since pregnant and postpartum patients tend to be young and have transient risk factors for VTE (eg, pregnancy, cesarean birth) [20,21]. (See "Overview of the treatment of proximal and distal lower extremity deep vein thrombosis (DVT)", section on 'Patients at high risk of bleeding' and "Treatment, prognosis, and follow-up of acute pulmonary embolism in adults", section on 'Inferior vena cava filter'.)

As IVC filters are generally inserted under fluoroscopy, we discuss with patients the potential risks of radiation to the fetus as well as to the mother [22-24]; use of iodinated contrast during pregnancy does not appear to pose any risk to the fetus. (See "Diagnostic imaging in pregnant and lactating patients", section on 'Use of iodinated contrast materials'.)

Studies evaluating the risks of fluoroscopy in pregnancy are limited. In one study using software calculations and model patients to evaluate radiation dose during IVC placement in pregnancy, total radiation dose to the fetus averaged approximately 2 milligray (mGy); cumulative radiation doses were slightly lower at later gestations compared with earlier gestations because part of the fetus was outside of the radiation field [22]. This is considerably lower than 50 mGy, which is the threshold at which adverse effects of radiation effects may be observed [25,26]. (See "Diagnostic imaging in pregnant and lactating patients", section on 'Dose threshold'.)

IVC filters placed during pregnancy also appear to be well tolerated, but data are limited [23,27-31]. In one review including 199 patients in whom an IVC filter was inserted during pregnancy, the risks of filter complications were comparable with the nonpregnant population [27]. However, inability to later retrieve a filter placed during the third trimester of pregnancy has been reported due to filter tilt, a feature that may be due to anatomical alterations in positioning during pregnancy or labor and delivery [31].

The insertion and complication of IVC filters are discussed separately. (See "Placement of vena cava filters and their complications".)

PATIENTS WITH LIFE-THREATENING THROMBOSIS — During pregnancy and the postpartum period, life-threatening venous thromboembolism (VTE) symptoms are mostly due to hemodynamically unstable PE. Less commonly, limb- and life-threatening symptoms are due to extensive proximal or iliofemoral DVT (eg, phlegmasia cerulea dolens). (See "Clinical presentation, evaluation, and diagnosis of the nonpregnant adult with suspected acute pulmonary embolism", section on 'Hemodynamically unstable patients' and "Clinical presentation and diagnosis of the nonpregnant adult with suspected deep vein thrombosis of the lower extremity", section on 'History'.)

Thrombolysis/thrombectomy — Similar to the nonpregnant population, the approach to management varies depending on the risk of bleeding:

●Most patients with life-threatening symptoms: Thrombolysis – For pregnant patients who present with life-threatening symptoms due to VTE, we evaluate for thrombolysis (table 3), typically with tissue plasminogen activator (systemic or catheter-directed for PE, catheter-directed for DVT). The principles of the evaluation are the same as for nonpregnant patients, although the risk-benefit ratio is altered due to the added potential of maternal, placental, or fetal hemorrhage. This evaluation is provided separately. (See "Approach to thrombolytic (fibrinolytic) therapy in acute pulmonary embolism: Patient selection and administration" and "Catheter-directed thrombolytic therapy in deep venous thrombosis of the lower extremity: Patient selection and administration".)

For life-threatening PE in nonpregnant patients, systemic thrombolysis is usually performed since it is universally available. However, in centers with available expertise and equipment, catheter-directed techniques may be preferred due to the likely reduction in the risk of major bleeding and ability by some techniques to perform mechanical thrombus extraction, although supportive data in pregnant patients are lacking. A PE response team can facilitate this decision. Limb- and life-threatening symptoms due to DVT are almost invariably performed using catheter-directed techniques. (See "Approach to thrombolytic (fibrinolytic) therapy in acute pulmonary embolism: Patient selection and administration", section on 'Catheter-directed approaches' and "Catheter-directed thrombolytic therapy in deep venous thrombosis of the lower extremity: Patient selection and administration", section on 'Route of administration (catheter-directed)'.)

While pregnancy is listed as a relative contraindication to thrombolysis (table 4), case reports and anecdotal evidence suggest successful use when reserved for life-threatening symptoms [32-40]. In a systematic review of case series including 83 pregnant patients with severe PE treated with thrombolytic therapy (mostly systemic alteplase), outcomes were as follows: maternal survival (94 percent), major bleeding postpartum (58 percent), major bleeding antepartum (17 percent), and fetal loss (possible related to PE or its treatment; 12 percent) [38]. In a subsequent meta-analysis including 141 pregnant patients who underwent thrombolysis, outcomes included: maternal death (2.8 percent), major bleeding (8.5 percent), fetal death (1.4 percent), miscarriage (6.4 percent), and preterm delivery (9.9 percent) [39].

Teratogenicity due to thrombolytic agents has not been reported.

●Patients in whom thrombolysis is not feasible: Thrombectomy – Surgical or catheter-directed thrombectomy may be the only option when thrombolytic therapy cannot be performed (eg, patients decline, bleeding risk is high, or thrombolysis is absolutely contraindicated (table 4)) or when thrombolysis fails.

Case reports of thrombectomy during pregnancy suggest that it can be used successfully as a life-saving measure, especially if thrombolysis fails [34,36,38]. In the systematic review of case series discussed above, 36 patients with severe PE were treated with thrombectomy; outcomes for the 36 patients treated with thrombectomy included: survival (86 percent), major bleeding (20 percent), and fetal death (possibly related to surgery; 20 percent) [38].

Factors that influence the decision to proceed with surgical thrombectomy are discussed separately. (See "Treatment, prognosis, and follow-up of acute pulmonary embolism in adults", section on 'Embolectomy' and "Approach to thrombolytic (fibrinolytic) therapy in acute pulmonary embolism: Patient selection and administration", section on 'Failure to improve or deterioration despite anticoagulation' and "Overview of the treatment of proximal and distal lower extremity deep vein thrombosis (DVT)", section on 'Thrombolytic therapy and thrombectomy' and "Catheter-directed thrombolytic therapy in deep venous thrombosis of the lower extremity: Patient selection and administration", section on 'Patients at high risk of bleeding or contraindications to thrombolysis' and "Catheter-directed thrombolytic therapy in deep venous thrombosis of the lower extremity: Patient selection and administration", section on 'Poor functional status, limited life expectancy, DVT >14 days'.)

Extracorporeal membrane oxygenation — In life-threatening cases, extracorporeal membrane oxygenation (ECMO), typically venoarterial ECMO, may be needed. ECMO can temporarily stabilize and oxygenate the patient while therapy is ongoing or act as a bridge to definitive therapy (eg, hemodynamic support during severe amniotic fluid embolism, cardiac arrest, or massive PE).

ECMO-related outcomes during pregnancy are mostly extrapolated from patients who undergo ECMO for acute respiratory distress syndrome, as data are limited in pregnant females with PE [38,41,42]. In one systematic review, among the 21 patients with high-risk PE treated with ECMO that was often combined with other therapies, maternal survival was 76 percent, fetal survival was 63 percent, and the rate of major bleeding was 55 percent [42].

The value of ECMO in nonpregnant patients with PE and other conditions is provided separately. (See "Treatment, prognosis, and follow-up of acute pulmonary embolism in adults", section on 'Extracorporeal membrane oxygenation' and "Extracorporeal life support in adults: Management of venoarterial extracorporeal membrane oxygenation (V-A ECMO)".)

THERAPIES OF UNCLEAR SIGNIFICANCE

Inferior vena cava filter predelivery — While not our routine practice, sometimes a temporary, retrievable inferior vena cava filter is placed in patients predelivery, which is discussed above. (See 'During pregnancy, labor and delivery, and postpartum' above and 'Patients at high bleeding risk or contraindications to anticoagulation: IVC filter' above.)

Planned delivery — For patients who have had high-risk PE or DVT during pregnancy, whether an induction of labor or cesarean birth is advisable is unknown. Typically, we wait for spontaneous vaginal delivery and only plan delivery using the typical indications. Multidisciplinary input may be useful in this regard. (See "Cesarean birth: Preoperative planning and patient preparation".)

RECURRENT VENOUS THROMBOEMBOLISM ON ANTICOAGULATION — For patients who develop recurrent venous thromboembolism while on anticoagulation, evaluation and management are similar to that in the nonpregnant population and depend on the etiology for recurrence (eg, subtherapeutic anticoagulation, suboptimal therapy, ongoing prothrombotic stimuli). This is discussed in detail separately. (See "Treatment, prognosis, and follow-up of acute pulmonary embolism in adults", section on 'Management of recurrence on therapy'.)

MONITORING AND FOLLOW-UP — Monitoring for complications of both VTE (eg, thrombus extension, recurrence) and anticoagulation (eg, bleeding, thrombocytopenia) is similar to nonpregnant patients. These issues are discussed separately. (See "Overview of the treatment of proximal and distal lower extremity deep vein thrombosis (DVT)", section on 'Monitoring and follow-up' and "Treatment, prognosis, and follow-up of acute pulmonary embolism in adults", section on 'Monitoring and follow-up'.)

Testing of patients with VTE in pregnancy for an inherited thrombophilia is controversial and is also discussed in detail separately. (See "Inherited thrombophilias in pregnancy", section on 'Selection of patients for testing' and "Inherited thrombophilias in pregnancy", section on 'When to test'.)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Superficial vein thrombosis, deep vein thrombosis, and pulmonary embolism" and "Society guideline links: Anticoagulation in pregnancy".)

SUMMARY AND RECOMMENDATIONS

●Multidisciplinary approach – Pregnancy and the postpartum period are well-established risk factors for deep vein thrombosis (DVT) and pulmonary embolism (PE), which are collectively referred to as venous thromboembolism (VTE). Since treatment differs from that in nonpregnant patients in several ways, we advocate for a multidisciplinary approach (eg, PE response team, pulmonology, maternal-fetal medicine, obstetric anesthesia, hematology, neonatology). (See 'Introduction' above and 'Multidisciplinary team' above.)

●Most patients – Anticoagulant therapy is the cornerstone of treatment. (See 'Indications' above and 'Most patients: Anticoagulation' above.)

•We assess the bleeding risk in all patients. The de novo risk of bleeding in most pregnant patients is low. However, the consequences associated with bleeding in patients who develop specific obstetric complications such as placental abruption and postpartum hemorrhage can lead to potentially devastating outcomes, thereby increasing this risk for pregnant patients in general. (See 'Assess bleeding risk' above.)

•In most pregnant patients with VTE, subcutaneous low molecular weight (LMW) heparin is the agent of choice (table 2); LMW heparin may be switched to unfractionated heparin in some patients prior to labor. Warfarin and direct oral anticoagulants are generally avoided in pregnancy. The rationale for LMW heparin, suitable agents for patients with acute renal failure or those who need rapid short-term control of anticoagulation, alternatives to heparin, and anticoagulant management during labor and delivery are discussed in detail elsewhere. (See 'During pregnancy, labor and delivery, and postpartum' above and "Use of anticoagulants during pregnancy and postpartum".)

•Some patients with VTE may have anticoagulant therapy initiated solely as an outpatient, typically LMW heparin. Such patients must be carefully selected and meet the same selection criteria as nonpregnant patients. These criteria are discussed separately. (See "Overview of the treatment of proximal and distal lower extremity deep vein thrombosis (DVT)", section on 'Outpatient versus inpatient therapy' and "Treatment, prognosis, and follow-up of acute pulmonary embolism in adults", section on 'Outpatient anticoagulation'.)

•For most pregnant patients whose only risk factor for VTE was transient (eg, pregnancy, cesarean birth), we suggest that the total duration of anticoagulant therapy be at least three months (Grade 2C). For those with VTE during pregnancy this duration should include the remainder of pregnancy and at least six weeks postpartum. (See 'Duration of therapy' above.)

●Patients at high bleeding risk or with contraindications to anticoagulation – For those in whom the bleeding risk is high or anticoagulation is contraindicated, placement of an inferior vena cava (IVC) filter is indicated. Indications for insertion of an IVC filter are the same in pregnant and nonpregnant patients and are discussed separately. (See "Overview of the treatment of proximal and distal lower extremity deep vein thrombosis (DVT)", section on 'Patients at high risk of bleeding' and "Treatment, prognosis, and follow-up of acute pulmonary embolism in adults", section on 'Inferior vena cava filter'.)

●Patients with life-threatening thrombosis – In most cases of life-threatening thrombosis, we evaluate patients for thrombolysis; if the bleeding risk is high or patients fail thrombolysis, we evaluate for thrombectomy. The principles of the evaluation are the same as for nonpregnant patients, although the risk-benefit ratio is altered due to the increased and added potential for maternal, placental, or fetal hemorrhage. Further details on this evaluation are provided separately:

•(See "Approach to thrombolytic (fibrinolytic) therapy in acute pulmonary embolism: Patient selection and administration".)

•(See "Catheter-directed thrombolytic therapy in deep venous thrombosis of the lower extremity: Patient selection and administration".)

•(See "Treatment, prognosis, and follow-up of acute pulmonary embolism in adults", section on 'Embolectomy'.)

●Recurrence and follow-up – The approach to recurrence and follow-up, including testing for inherited thrombophilias, is discussed in detail separately:

•(See "Overview of the treatment of proximal and distal lower extremity deep vein thrombosis (DVT)", section on 'Monitoring and follow-up'.)

•(See "Treatment, prognosis, and follow-up of acute pulmonary embolism in adults", section on 'Monitoring and follow-up'.)

•(See "Inherited thrombophilias in pregnancy", section on 'Selection of patients for testing'.)

ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges David R Schwartz, MD, who contributed to earlier versions of this topic review.