Background
Prophylactic anticoagulation is usually recommended for six weeks postpartum (PPM) for individuals at high risk of developing venous thromboembolism (VTE). However, there are no randomized controlled trials (RCTs) assessing optimal duration of prophylactic anticoagulation post-partum. Moreover, the risk is not equivalent throughout the six weeks as evidenced by a sharp decline in VTE risk following the third week PPM. These observations call into question the optimal duration of PPM thromboprophylaxis and whether a full six weeks is needed.
Objective
This study sought to determine postpartum anticoagulation practices and to explore practitioners' willingness to consider reduction of the duration of PPM prophylactic anticoagulation.
Methods
We conducted a cross-sectional study between December 2022 and April 2023 using a self-administered electronic questionnaire on the ‘SurveyMonkey’ platform to gauge international preferences for the use, dose and duration of postpartum anticoagulation . The survey was validated for face and content validity and explored expert preferences across complex PPM scenarios. Physician characteristics, years in practice, specialty and continent of practice were also collected. We employed various methods of dissemination including email, scientific conferences, expert groups, and social media.
Results
Of the 113 participants that responded to the initial invitation, 78 completed the survey with the following regional distribution: 53.9% from Europe, 23.1% from North America, and 19.0% from Australia and New Zealand. Among the respondents, 60% were haematologists, 20% were general obstetric physicians, and 13% were maternal-fetal medicine (MFM) experts.
For prior unprovoked or hormone-associated deep venous thrombosis (DVT) or pulmonary embolism (PE), non-hormone associated provoked DVT/PE, cerebral venous sinus thrombosis (CVST) and splanchnic vein thrombosis, 97.4%, 93.5%, 91.0% and 88.5% of experts selected six weeks of prophylactic anticoagulation with LMWH postpartum compared to 3 weeks or prophylaxis with unfractionated heparin. This practice was also supported by 70.5%, 78.2% and 87.2% of experts in individuals with sickle cell disease (SCD), obstetric antiphospholipid syndrome (APS) and high-risk thrombophilia, respectively.
For individuals with a history of unprovoked PE/DVT or history of thrombosis at atypical sites (splanchnic thrombosis or CVST) approximately half of the experts (48.7% and 47.4 %) were willing to offer thromboprophylaxis with 3 weeks of LMWH followed by 3 weeks of aspirin, while approximately one-third (34.6% and 32.1%) would consider 3 weeks of LMWH only (Table 1). Respondents managing more than 10 patients per year (p=0.0001), with over 5 years of practice experience (p=0.0004) and specialization in Haematology or MFM demonstrated a greater willingness to explore shorter durations.
For scenarios of individuals with SCD, obstetric APS and myeloproliferative neoplasms (MPNs), with no history of VTE, a higher percentage of respondents (69.2%, 60.3%, 67.9%) would support 3 weeks of LMWH followed by 3 weeks of aspirin or no anticoagulation PPM (Table 1). For SCD, Haematologists were slightly less supportive (68.1%) than MFM (80%) and obstetric medicine physicians (75%) of shorter durations, although the difference was not statistically significant (p=0.45). For MPNs, Haematologists were more supportive of shorter durations (76.6%) than MFMs (60%) and obstetric medicine physicians (50%) (p=0.047). For obstetric APS, there was no significant difference amongst the specialties with respect to explore shorter anticoagulation durations.
Conclusion
The majority of experts (90%) prescribe a 6 week LMWH regimen for patients with a background of DVT/PE, thrombosis in atypical sites, or high-risk thrombophilias, while fewer adopt this approach for SCD, obstetric APS. Half of the specialists would consider shorter durations of prophylactic anticoagulation PPM for individuals with prior DVT/PE, thrombosis in atypical sites and even more (60-70%) for SCD, obstetric APS and MPNs. Experience and caseload influence acceptance of shorter durations. There is an urgent need for prospective studies addressing peripartum management of anticoagulation such as appropriate type, dosage, initiation timing and duration in different diseases, to provide evidence regarding optimal strategies.
Disclosures
No relevant conflicts of interest to declare.
