Thromboprophylaxis after cesarean section: decision analysis

Guideline-based venous thromboprophylaxis in postpartum women: An in-depth evaluation of ACOG and RCOG recommendations and real-life implementation

OBJECTIVES

Venous thromboembolism is one of the most serious complications of the postpartum period, and international societies have various thromboprophylaxis guidelines for its prevention. This study compares postpartum venous thromboprophylaxis recommendations from the American College of Obstetrics and Gynecology (ACOG) and the Royal College of Obstetricians and Gynecologists (RCOG) with real-life clinical practices.

STUDY DESIGN

Data analysis of 1000 postpartum women at a tertiary care center focused on patient demographics, venous thromboembolism risk factors, and clinical thromboprophylaxis practices. Patient-specific risk factors were compared between ACOG and RCOG guidelines, assessing Low-Molecular-Weight-Heparin dosages and durations. Guideline compliance, undertreatment/overtreatment rates, and the required number of prefilled Low-Molecular-Weight-Heparin syringes were evaluated.

RESULTS

Significant discrepancies were observed between ACOG and RCOG guidelines, particularly in Low Molecular Weight Heparin dosages and durations. Consensus rates with clinical approaches were around 53%, with inconsistencies leaning towards undertreatment (RCOG) and overtreatment (ACOG). The number of required prefilled Low-Molecular-Weight-Heparin syringes was notably higher according to RCOG compared to ACOG guidelines.

CONCLUSION

Postpartum Venous thromboembolism prophylaxis guidelines from American College of Obstetrics and Gynecology and Royal College of Obstetricians and Gynecologists exhibit substantial differences, leading to variations in clinical practice. Further research on the significance of Venous thromboembolism risk factors is essential for improving risk assessment tools and refining guideline recommendations for pregnancy-related Venous thromboembolism prevention.

Projected impact of guidelines on incidence of venous thromboembolism after cesarean delivery in the United States

BACKGROUND

There is large variation in recommended for postcesarean delivery venous thromboembolism (VTE) prophylaxis among commonly used guidelines.

OBJECTIVES

The aim of the study is to estimate implications of adoption of VTE prevention guidelines for rates of receipt of VTE prophylactic therapy and VTE following cesarean delivery (CD).

METHODS

We used administrative data from the 2015-2019 Nationalwide Readmissions Database to identify cesarean deliveries and rates of VTE stratified by risk factors, leading to different prophylactic strategies based on several national guidelines. We used input parameters from the literature to construct a hybrid decision tree/Markov model to project the implications of guideline adoption on VTE rates for the first 6 weeks following delivery.

RESULTS

Adoption of either the 2011 American College of Obstetricians and Gynecologists or the 2018 American Society for Hematology guidelines would avert a relatively small proportion (5%) of VTE cases, albeit with little low-molecular-weight heparin (LMWH) use (87-115 doses per 1000 CD patients). The 2012 American College of Chest Physicians guidelines were predicted to be more effective at averting VTE (21.2% reduction) with more LMWH usage (570 doses per 1000 deliveries). The 2015 Royal College of Obstetricians and Gynaecologists guidelines and universal use of 6 weeks of LMWH would avert an even larger proportion of cases (37.4% and 57.6%, respectively), at the cost of much higher rates of LMWH utilization (7233 doses per 1000 patients and 38 648 doses per 1000 patients).

CONCLUSIONS

Adoption of different guidelines would have notably varying implications for clinical practice and potential for alteration of the national rate of VTE following CD.

Prevention and management of venous thromboembolism in pregnancy: cutting through the practice variation

There is clinical practice variation in the area of prevention and management of venous thromboembolism (VTE) in pregnancy. There are limited data and differing recommendations across major clinical practice guidelines, especially relating to the role of postpartum low-molecular-weight heparin (LMWH) for patients with mild inherited thrombophilia and those with pregnancy-related VTE risk factors. This chapter explores the issues of practice variation and related data for postpartum VTE prevention. Controversial topics of VTE management in pregnancy are also reviewed and include LMWH dosing and the role of anti-Xa level monitoring, as well as peripartum anticoagulation management around labor and delivery.

Estimating the risk thresholds used by guidelines to recommend postpartum thromboprophylaxis

BACKGROUND

Guidelines for postpartum thromboprophylaxis are mostly expert based. Acceptable postpartum venous thromboembolism (VTE) risk thresholds to justify the use of thromboprophylaxis are ill defined.

OBJECTIVE

To compare the proportion of postpartum women with recommended thromboprophylaxis according to the Royal College of Obstetricians and Gynecologists (RCOG), American College of Obstetricians and Gynecologists (ACOG), and American College of Chest Physicians (ACCP) guidelines, and to estimate their threshold of risk of VTE.

METHODS

We collected maternal, obstetrical, and fetal characteristics among all women who delivered at the Geneva University Hospitals in January 2019 through medical chart review. We determined for each woman the recommended strategy of thromboprophylaxis according to each guideline. We indirectly estimated individual absolute VTE risks using a validated risk prediction model (Sultan).

RESULTS

Among 344 women (mean age 32.2 years), with 23.3% of cesarean deliveries (CD), the RCOG guideline categorized 40.1% of all deliveries, 25.4% of vaginal deliveries (VD), and 88.8% of CD as requiring thromboprophylaxis. The ACOG and ACCP guidelines, which focus on CD, categorized fewer women as high risk (35.0% and 40.0% of CD, respectively). The mean estimated risk of VTE was 0.07% in all participants, 0.12% in those with recommended thromboprophylaxis according to the RCOG, and 0.20% among women after CD with recommended thromboprophylaxis by the ACOG and ACCP guidelines.

CONCLUSIONS

Our data highlight important variations in the proportion of thromboprophylaxis recommendation between guidelines. Risk thresholds to recommend the use of heparin appear very low, and may correlate with a high, and perhaps undesirable, number needed to treat to prevent VTE events.

Current opinion and emerging trends on the treatment, diagnosis, and prevention of pregnancy-associated venous thromboembolic disease: a review

Pregnancy associated venous thromboembolism (PA-VTE) is a leading cause of maternal morbidity and mortality worldwide. Despite the availability of international guidance on the prevention, diagnosis and treatment, practice differs between countries and clinical institutions. The evidence base in this area is limited due to the vulnerable population who are affected, with the majority of guidelines deriving their recommendations from experience in surgical and medical venous thromboembolic disease. This review includes best evidence in PA-VTE management, highlighting specific literature which supports current diagnosis, prevention, and treatment strategies. Additionally, we hope to demonstrate emerging trends in the field through discussion of ongoing trials designed to progress towards evidence-based practice in the context of PA-VTE.

United Kingdom recommendations for obstetric venous thromboembolism prophylaxis: Evidence and rationale

Venous thromboembolism (VTE) is a leading cause of maternal death in the United Kingdom. To address this problem guidance from the Royal College of Obstetricians and Gynaecologists (RCOG) has been developed that recommends the assessment of a woman's risk of thrombosis at specific time-points during pregnancy and postnatally at the time of delivery. The RCOG guidelines provide clinicians with a framework to inform decision-making on the use of thromboprophylaxis and are based on the premise that the higher risk a woman has for VTE, the more likely she is to benefit from prophylaxis - determining her level of risk is based on the number and characteristics of the risk factors that she has. This article will address the pathophysiology of VTE in pregnancy, evidence behind the risk factors for VTE and the use of thromboprophylactic agents. Further, it will reflect on the rationale behind the RCOG guidance.

Utilization of venous thromboembolism prophylaxis in American hospitalized pregnant women undergoing cesarean section

Background Pregnancy-related venous thromboembolism (VTE) is a leading preventable cause of maternal mortality in the United States; however, American guidelines for pharmacologic VTE prophylaxis remain less aggressive than other developed countries. The Safe Motherhood Initiative (SMI) combines aspects of American and international guidelines to increase utilization of prophylaxis and thereby decrease incidence of pregnancy-related VTE. Objectives To evaluate the prescribing and administration rates of pharmacologic VTE prophylaxis for women undergoing cesarean section (c-section) when retrospectively applying the SMI recommendations. Setting Large academic medical center in Sacramento, California, USA. Method This was a single-center retrospective cohort study of pregnant women undergoing c-section who would have met criteria for pharmacologic prophylaxis according to the SMI. Main outcome measures Prescribing and administration rates of mechanical and pharmacologic VTE prophylaxis. Secondary outcomes included incidence of thromboembolism within 6 weeks after c-section and thromboembolic associated mortality. Results A total of 616 charts were analyzed. When applying the SMI guidelines for VTE prophylaxis, the prescribing rates for mechanical and pharmacologic prophylaxis were 94.3% and 4.71% of patients, respectively, and 94.9% of ordered pharmacologic prophylaxis doses were administered. The incidence of 6-week post-partum VTE was 0.49%. There were no cases of VTE-associated mortality. Conclusion This study demonstrated that a large population of c-section patients fit the SMI criteria for pharmacologic VTE prophylaxis but did not receive it. We observed a 0.49% rate of VTE, which was slightly higher than the nationally reported average rate of 0.3%. With growing rates of pregnancy-associated VTE in the United States, perhaps a more aggressive guideline is warranted.

Anesthesia implications of coagulation and anticoagulation during pregnancy

Coagulation is an organized and well-orchestrated process that depends on the intrinsic balance between procoagulants, anticoagulants, and fibrinolytic systems. During pregnancy, this balance is affected in various ways and becomes more critical due to the physiologic changes and obligate hemorrhage after delivery. In some instances, this equilibrium will be disrupted. In this article, we describe the anesthetic implications of bleeding disorders, thrombophilias, and anticoagulation for the safe management of the parturient, with an emphasis on how this impacts decision-making by the anesthesiologist.