From the Guidelines
Postpartum coagulation is characterized by a hypercoagulable state, with increased fibrinogen levels and clotting factors, which requires close clinical observation and monitoring, particularly in patients with congenital fibrinogen disorders, to prevent secondary postpartum hemorrhage (PPH) and thrombotic events. The coagulation changes postpartum are significant, with a rapid increase in clotting factors, particularly fibrinogen, which should be targeted to a level ≥1.5 g/L for 3 days after vaginal delivery and 5 days after cesarean section, as suggested by the study published in the Journal of Thrombosis and Haemostasis 1. Some key points to consider in the management of postpartum coagulation include:
- Close clinical observation and monitoring of postpartum fibrinogen levels
- Consideration of tranexamic acid (TXA) to prevent secondary PPH and prolonged or heavy lochia, depending on the thrombotic risk
- Pharmacologic thromboprophylaxis with low molecular weight heparin (LMWH) until discharge, especially in cases with additional thrombotic risk factors, as recommended by the study 1
- Potential extension of thromboprophylaxis to 4 to 6 weeks on fibrinogen prophylaxis, depending on the patient’s phenotype and other thrombotic risk factors, as suggested by the study 1. Understanding these coagulation changes is essential for appropriate management of postpartum hemorrhage and thromboprophylaxis, as the balance between bleeding risk and clotting risk is delicate during this period, and the risk of venous thromboembolism (VTE) is increased by 5-10 fold compared to non-pregnant women.
From the Research
Changes in Coagulation Postpartum
The postpartum period is associated with an increased risk of venous thromboembolism (VTE) due to the physiological tendency towards a hypercoagulable state from conception to the postpartum period 2. Several studies have investigated the changes in coagulation postpartum, including the incidence and risk factors for VTE.
Incidence and Risk Factors for VTE
The incidence of postpartum VTE is highest during the first 3 weeks after delivery, with a significant decrease in incidence after 4 weeks 3. Certain obstetric procedures and complications, such as cesarean delivery, preeclampsia, hemorrhage, and postpartum infection, confer an increased risk for VTE, which persists over the 12-week period after delivery 3. Non-obstetric risk factors, such as a history of thromboembolic events and thrombophilic factors, also increase the risk of VTE 4.
Coagulation Changes and VTE Prevention
Pregnancy itself, cesarean delivery, and the postpartum period are associated with an increased risk of VTE, although this risk is minor when not combined with other risk factors 4. Prophylactic treatment with low molecular weight heparins is effective in preventing VTE, with the dose and duration of treatment adapted to the perceived level of risk 4. A study comparing two weight-based protocols for enoxaparin administration found that a dose of 1 mg/kg was superior to weight categories in achieving prophylactic anti-Xa levels without leading to serious adverse effects 5.
Diagnostic and Management Approaches
Diagnosis of VTE in the postpartum period can be challenging due to overlapping symptoms with normal pregnancy, requiring a high index of suspicion and the use of diagnostic tools such as D-dimer, ultrasonography, and computed tomography pulmonary angiography 2. Management of VTE mainly involves systemic anticoagulation with heparin, with advanced therapy options available for selected high-risk cases 2. Imaging techniques, including US and contrast-enhanced CT, play a crucial role in the assessment of postpartum complications, including thrombotic complications such as deep vein thrombosis and ovarian vein thrombophlebitis 6.
Key Findings
- The postpartum period is associated with an increased risk of VTE due to a hypercoagulable state 2.
- The incidence of postpartum VTE is highest during the first 3 weeks after delivery 3.
- Certain obstetric procedures and complications increase the risk of VTE, which persists over the 12-week period after delivery 3.
- Prophylactic treatment with low molecular weight heparins is effective in preventing VTE, with the dose and duration of treatment adapted to the perceived level of risk 4.
- A dose of 1 mg/kg enoxaparin is superior to weight categories in achieving prophylactic anti-Xa levels without leading to serious adverse effects 5.