Deep Venous Thrombosis and Pulmonary Embolism in Pregnancy

Pulmonary thrombo-embolism in pregnancy: diagnosis and management

KEY POINTS

Venous thromboembolism (VTE) in pregnancy remains a leading cause of direct maternal mortality in the developed world and identifiable risk factors are increasing in incidence.VTE is approximately 10-times more common in the pregnant population (compared with non-pregnant women) with an incidence of 1 in 1000 and the highest risk in the postnatal period.If pulmonary imaging is required, ventilation perfusion scanning is usually the preferred initial test to detect pulmonary embolism within pregnancy. Treatment should be commenced on clinical suspicion and not be withheld until an objective diagnosis is obtained.The mainstay of treatment for pulmonary thromboembolism in pregnancy is anticoagulation with low molecular weight heparin for a minimum of 3 months in total duration and until at least 6 weeks postnatal. Low molecular weight heparin is safe, effective and has a low associated bleeding risk.

EDUCATIONAL AIMS

To inform readers about the current guidance for diagnosis and management of pulmonary thromboembolism in pregnancy.To highlight the risks of venous thromboembolism during pregnancy.To introduce the issues surrounding management of pulmonary thromboembolism around labour and delivery.

Women's values and preferences for thromboprophylaxis during pregnancy: a comparison of direct-choice and decision analysis using patient specific utilities

BACKGROUND

Women with a history of venous thromboembolism (VTE) have an increased recurrence risk during pregnancy. Low molecular weight heparin (LMWH) reduces this risk, but is costly, burdensome, and may increase risk of bleeding. The decision to start thromboprophylaxis during pregnancy is sensitive to women's values and preferences. Our objective was to compare women's choices using a holistic approach in which they were presented all of the relevant information (direct-choice) versus a personalized decision analysis in which a mathematical model incorporated their preferences and VTE risk to make a treatment recommendation.

METHODS

Multicenter, international study. Structured interviews were on women with a history of VTE who were pregnant, planning, or considering pregnancy. Women indicated their willingness to receive thromboprophylaxis based on scenarios using personalized estimates of VTE recurrence and bleeding risks. We also obtained women's values for health outcomes using a visual analog scale. We performed individualized decision analyses for each participant and compared model recommendations to decisions made when presented with the direct-choice exercise.

RESULTS

Of the 123 women in the study, the decision model recommended LMWH for 51 women and recommended against LMWH for 72 women. 12% (6/51) of women for whom the decision model recommended thromboprophylaxis chose not to take LMWH; 72% (52/72) of women for whom the decision model recommended against thromboprophylaxis chose LMWH.

CONCLUSIONS

We observed a high degree of discordance between decisions in the direct-choice exercise and decision model recommendations. Although which approach best captures individuals' true values remains uncertain, personalized decision support tools presenting results based on personalized risks and values may improve decision making.

Increase in maternal death-related venous thromboembolism during pregnancy in Japan (2010-2013)

BACKGROUND

The aim of the present work was to understand the current circumstances of maternal-death-related venous thromboembolism (MD-VTE) in Japan. We retrospectively investigated the characteristics of cases of MD-VTE, and compared past and present rates of occurrence.

METHODS AND RESULTS

We examined the Japanese data for MD-VTE in 2010-2013, and compared it with that from 1991-1992. MD-VTE occurred in 17 women in 1991-1992, and in 13 women in 2010-2013. The maternal mortality ratio of MD-VTE was 0.7 per 100,000 in 1991-1992 and 0.4 per 100,000 in 2010-2013. Both the maternal mortality ratio and rate of MD-VTE in 2010-2013 deceased significantly compared with 1991-1992 (P<0.05). However, the number of cases of MD-VTE during pregnancy was 6 among 13 women (41%) in 2010-2013, but 1 in 17 women (6%) in 1991-1992, showing an increase (P<0.05). In the present study, cesarean delivery was more frequently associated with MD-VTE.

CONCLUSIONS

MD-VTE overall has decreased within the past 20 years in Japan. But, MD-VTE during pregnancy in 2010-2013 increased relative to 1991-1992. Future guidelines for prevention of VTE may need to extend beyond the perioperative period to decrease the incidence of MD-VTE.

Management of cardiovascular diseases during pregnancy

The prevalence of cardiovascular diseases (CVDs) in women of childbearing age is rising. The successes in medical and surgical treatment of congenital heart disease have led to an increasing number of women at childbearing age presenting with problems of treated congenital heart disease. Furthermore, in developing countries and in immigrants from these countries, rheumatic valvular heart disease still plays a significant role in young women. Increasing age of pregnant women and increasing prevalence of atherosclerotic risk factors have led to an increase in women with coronary artery disease at pregnancy. Successful management of pregnancy in women with CVDs requires early diagnosis, a thorough risk stratification, and appropriate management by a multidisciplinary team of obstetricians, cardiologists, anesthesiologists, and primary care physicians. The following review is based on the recent European guidelines on the management of CVDs during pregnancy, which aim at providing concise and simple recommendations for these challenging problems.

Use of fondaparinux in a pregnant woman with pulmonary embolism and heparin-induced thrombocytopenia

BACKGROUND

A serious complication of heparin treatment, heparin-induced thrombocytopenia (HIT) is rarely observed in pregnant women. Drug therapy during pregnancy should always be chosen to minimize fetal risk. The management of HIT in pregnancy represents a medical challenge. Unlike heparins, the anticoagulants used in patients with HIT do cross the placenta, with unknown fetal effects.

CASE REPORT

We present a case of a 24-year-old female presenting for care at 34 weeks of gestation with acute pulmonary embolism treated initially with unfractionated heparin (UFH) and low molecular weight heparin (LMWH), who developed HIT. She was then successfully treated with fondaparinux.

CONCLUSIONS

To the best of our knowledge, this is one of the first case reports describing a successful use of fondaparinux in the treatment of HIT in a third-trimester pregnant woman, providing a novel approach for this subset of patients.

Epidemiology of pregnancy-associated venous thromboembolism: a population-based study in Canada

OBJECTIVE

To estimate the frequency of, and to identify risk factors for, pregnancy-associated venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE) requiring hospitalization.

METHODS

We conducted a population-based cohort study (N = 3 852 569) using the Discharge Abstract Database of the Canadian Institute for Health Information (CIHI), for the fiscal years 1991-1992 to 2005-2006. All women with pregnancy-related hospitalizations in Canada (excluding Quebec and Manitoba) were identified. DVT and PE rates were calculated using the number of hospital deliveries (i.e., cohort of women at risk) as the denominator for the antepartum and peripartum (labour and delivery) hospitalizations and for postpartum readmissions. Risk factors for DVT/PE were identified using logistic regression.

RESULTS

During the antepartum, peripartum, and postpartum periods, 5.4, 7.2, and 4.3 VTE cases per 10,000 pregnancies, respectively were observed. The total incidence of DVT was 12.1 per 10,000 pregnancies (0.26 deaths per 100,000), and the rate for PE was 5.4 per 10,000 (0.96 deaths per 100,000). The strongest risk factors for DVT occurrence during the peripartum period were thrombophilia (adjusted odds ratio [aOR] 15.4; 95% CI 10.8-22.0), a past history of circulatory disease, and major puerperal infection, whereas those for PE were previous DVT (aOR 56.9; 95% CI 40.9-79.1), heart disease (aOR 43.4, 95% CI 35.0-53.9), antiphospholipid syndrome, past history of circulatory disease, transfusion, and major puerperal infection.

CONCLUSION

Cases of VTE and associated deaths occur most frequently during the peripartum period. Although mortality from pregnancy-associated VTE is low, maternal characteristics and other factors can be used to identify women at risk for VTE.

Pulmonary thromboembolism in obstetrics and gynecology increased by 6.5-fold over the past decade in Japan

BACKGROUND

Although pulmonary thromboembolism (PTE) has been considered relatively uncommon in Japan, its incidence has been on the increase in recent years.

METHODS AND RESULTS

To verify the incidence of PTE in Japan, PTE cases of obstetrics and gynecology were investigated among 102 facilities throughout Japan between 1991 and 2000. A total of 254 cases were enrolled, showing a 6.5-fold increase over the past 10 years. PTE occurred in 0.02% of total births; 0.003% after vaginal deliveries and 0.06% after cesarean births (C/S), of which 14.5% resulting in fatality. The mortality rate was 2.5 per 100,000 deliveries. The incidences among gynecological cases were 0.08% of total operations; 0.03% in benign diseases and 0.42% in malignant diseases of which 13.5% resulting in fatality. The mortality rate was 10.8 per 100,000 operations. The risk was 22 times higher in C/S compared with vaginal deliveries, 16 times higher in malignant diseases compared with benign diseases.

CONCLUSIONS

As our present survey has shown, PTE has been on the rise in Japan in recent years. C/S and malignant diseases are strong risk factors in obstetrics and gynecology.

Guidelines on the diagnosis and management of acute pulmonary embolism: the Task Force for the Diagnosis and Management of Acute Pulmonary Embolism of the European Society of Cardiology (ESC)

Non-thrombotic PE does not represent a distinct clinical syndrome. It may be due to a variety of embolic materials and result in a wide spectrum of clinical presentations, making the diagnosis difficult. With the exception of severe air and fat embolism, the haemodynamic consequences of non-thrombotic emboli are usually mild. Treatment is mostly supportive but may differ according to the type of embolic material and clinical severity.

Forensic Lung Pathology

Sudden and unexpected natural deaths and nonnatural deaths may result from various pulmonary conditions. Additionally, several nonpulmonary conditions of forensic significance may be complicated by the development of respiratory lesions. Certain situations with pulmonary pathology are particularly likely to be critically scrutinized and may form the basis of allegations of medical negligence, other personal injury liability, or wrongful death.1

Pulmonary embolism during and after pregnancy

BACKGROUND

Venous thromboembolic disease is among the most common causes of morbidity and mortality during pregnancy. The clinical evaluation alone is insufficient for the diagnosis of venous thromboembolic disease, and the normal pregnant state makes this evaluation even more challenging.

DIAGNOSIS

Objective testing is the mainstay of diagnosis, including compression ultrasound, impedance plethysmography, ventilation-perfusion scanning, computed tomography scanning, and pulmonary angiography. All of these tests can be safety performed during pregnancy.

TREATMENT

If deep vein thrombosis or pulmonary embolism is diagnosed, anticoagulation should be initiated. Either (unfractionated) heparin or low molecular weight heparin is an acceptable treatment for acute venous thromboembolic disease. Both have risks and benefits, but both can be used safely during pregnancy. Intravenous heparin is the treatment of choice surrounding delivery due to its short half life. Because of the risk of adverse effects on the fetus, warfarin is not generally used during pregnancy. Unstable pulmonary embolism is difficult to treat during pregnancy, as there are minimal data regarding the safety and efficacy of thrombolytic therapy, inferior vena cava filters, and embolectomy during pregnancy. Case reports and case series suggest that thrombolytic therapy may be associated with lower risks of fetal loss than embolectomy.

CONCLUSIONS

Venous thromboembolic disease is a significant cause of morbidity and mortality during pregnancy and the puerperal period. Objective testing is critical to establish the diagnosis and can be safely performed during pregnancy. Anticoagulation with heparin is the mainstay of therapy during the pregnancy, but patients may be transitioned to warfarin after delivery.

Cost-effectiveness of prophylactic low molecular weight heparin in pregnant women with a prior history of venous thromboembolism

PURPOSE

Women with a history of prior venous thromboembolism have an increased risk for recurrence during pregnancy. Although thromboprophylaxis reduces this risk, recent evidence suggests that, in many cases, prophylaxis can be safely withheld because the estimated recurrence risk is very low. The balance of risks and benefits in women with different recurrence risks has not been examined.

METHODS

We developed a Markov state transition decision analytic model to compare prophylactic low molecular weight heparin to expectant management for pregnant women with a single prior venous thromboembolism. A lifetime time horizon and societal perspective were assumed. Input data were obtained by literature review. Outcomes were expressed as U.S. dollars per quality-adjusted life-year (QALY).

RESULTS

For "low-risk" women with a prior venous thromboembolism associated with a transient risk factor and no known thrombophilic condition (recurrence risk 0.5%), expectant management was both more effective and less costly than prophylaxis. For "high-risk" women with prior idiopathic venous thromboembolism or known thrombophilic condition (recurrence risk 5.9%), prophylaxis was associated with a reasonable cost-effectiveness ratio (USD 38,700 per QALY) given a risk of bleeding complications <1.0% (base case 0.5%).

CONCLUSION

For low-risk women with prior venous thromboembolism, expectant management during pregnancy leads to better outcomes than administration of prophylactic low molecular weight heparin. For high-risk women, antepartum thromboprophylaxis is a cost-effective use of resources.

Pulmonary embolism and pregnancy

Pulmonary embolism is a significant cause of morbidity and mortality during pregnancy and the puerperium. The spectrum of venous thromboembolism is difficult to diagnose. Objective diagnostic testing is crucial and should not be delayed. Anticoagulation is the mainstay of therapy for deep vein thrombosis and pulmonary embolism. Most of the literature and practice protocols for the treatment of pregnant women are based on data extrapolated from the nonpregnant population, and more research is needed to improve the understanding of the efficacy and safety of testing and therapy in the pregnant population.

Thromboembolism prophylaxis and cesarean section: a survey of general obstetricians

BACKGROUND

Venous thromboembolism (VTE) has historically remained a risk factor for obstetric patients, particularly those requiring cesarean section. The objective of this survey was to assess the response of general obstetricians to risk factor considerations for VTE prophylaxis and cesarean section.

METHODS

A survey regarding VTE prophylaxis and cesarean section was sent to 113 obstetricians practicing in suburban Chicago and northern Wisconsin.

RESULTS

There were 51 responses (45%) to the survey. Most respondents do not routinely use VTE prophylaxis for cesarean section in patients who may have one or more risk factors.

CONCLUSION

There appears to be lack of consensus or appreciation for VTE and prophylaxis for cesarean section. Further studies and education are warranted.

Venous thromboembolism and pregnancy

Venous thromboembolism remains a major cause of maternal morbidity and mortality. Pregnancy is a thrombogenic state; therefore, clinicians must be familiar with the diagnosis and treatment of acute VTE. It is of paramount importance when caring for pregnant women to understand which patients are at risk for VTE and to use thromboprophylactic heparin accordingly.

Medical problems during pregnancy

Dramatic physiologic changes are part of normal human pregnancy. The physiologic alterations of pregnancy have the potential to affect chronic diseases, to unmask subclinical conditions, or to alter the presentation and course of newly acquired illnesses. An update in selected topics of obstetric medicine follows, focusing on clinical entities in which there have been significant advances in diagnosis or management. Additionally, reviews of selected medical disorders, such as HIV infection and asthma, that are rising in incidence in women of reproductive age are included.

Cardiac arrest due to massive pulmonary embolism following caesarean section. Successful resuscitation and pulmonary embolectomy

A woman developed pulmonary embolism with cardiac arrest after caesarean section. Cardiopulmonary resuscitation was performed for 45 min during which echocardiography showed right ventricular dilatation. After stabilization, but still in a critical condition, the patient was transferred by airambulance to a hospital with facilities for extracorporeal circulation. A massive embolus was removed. Some hours after extubation the patient developed respiratory insufficiency and hypovolaemia. Re-intubation was followed by severe hypotension requiring external cardiac compression for about 15 min. An emergency explorative laparotomy revealed a ruptured liver with a subcapsular haematoma. A critical illness polyneuropathy made prolonged ventilatory support necessary. She recovered without cerebral sequelae.

Deep vein thrombosis in pregnancy and the puerperium: a comprehensive review

Although uncommon during pregnancy and the postpartum period, deep vein thrombosis (DVT) and its sequela, pulmonary thromboembolism, remain leading sources of maternal mortality and morbidity. The majority of literature concerning DVT in pregnancy and the postpartum period exists in the medical journals, with only a small amount in nursing journals. This article provides the nursing community a comprehensive review of literature concerning the incidence of both DVT and pulmonary embolism in pregnancy and the postpartum period, identification of risk factors, the effectiveness of available screening and diagnostic tools, and finally, options for treatment and prophylaxis.

Use of recombinant tissue-type plasminogen activator to treat massive pulmonary embolism after cesarean section: a case report

A 30-year-old primigravida, delivering by cesarean section, went into shock with cardiac arrest due to pulmonary thromboembolism. Thrombolytic therapy with recombinant-tissue-type plasminogen activator (rt-PA) induced a rapid improvement in both the hemodynamic and respiratory conditions. This case shows the marked efficacy of rt-PA in treating massive pulmonary thromboembolism. Close attention must be given to the patient in such a case, however, because the risk of hemorrhagic complication exists.