Management of individuals with bleeding or thrombotic disorders undergoing abortion: Part 2

Some individuals are at high risk for thrombosis during their pregnancies, and clinical recommendations from expert groups have recommended antenatal anticoagulation for several specific groups, although the certainty of evidence is low.

The American Society of Hematology guidelines (2018) recommend antenatal anticoagulation at prophylactic doses for women at high risk for VTE:

1. Women with a personal history of unprovoked or hormonally provoked VTE

2. Women with antithrombin deficiency and a family history of VTE

3. Women with homozygosity for factor V Leiden or combined factor V Leiden/prothrombin gene mutation regardless of family history

The use of VTE prophylaxis in pregnant women with a history of VTE reduces the risk of recurrent VTE by approximately 75%, which is similar to the risk reduction seen with VTE prophylaxis following high-risk orthopedic procedures. It can be assumed that the risk reduction when prophylaxis is in the period surrounding abortion would be similar.

Since there are no teratogenic effects to limit the choice of anticoagulants in an abortion patient, any of the standard anticoagulants would be appropriate. LMWH is recommended at standard prophylactic doses or intermediate doses in the postpartum setting. Warfarin is recommended at doses to produce an INR of 2- 3. In the rare case that a pregnancy continues in a patient taking warfarin, the patient should be counseled regarding the risks of warfarin embryopathy. By extension, prophylactic doses of the direct oral anticoagulants would also be a possible option. If there is concern or question about the appropriate agent to start, a hematologist should be consulted.

Individuals who meet the criteria for antenatal anticoagulation should be instituted on anticoagulation if the abortion procedure is not going to take place in the immediate future. There is not enough evidence to recommend that a procedure be delayed specifically to start anticoagulation. Authors would recommend LMWH given in standard prophylactic doses (the equivalent of 40 mg daily of enoxaparin) prior to the procedure, stopping it 24 hours in advance of the abortion.

There is no evidence on how long the period of increased risk of VTE persists after abortion. The postpartum guidelines recommend 6 weeks of postpartum prophylaxis in women with prior VTE and with some inherited thrombophilias. There is no evidence regarding the optimal duration of anticoagulation. Using the fall in risk after a full-term pregnancy as a guideline, a duration of 4-6 weeks after an abortion would be reasonable.

All individuals should undergo an individualized risk assessment for VTE when they present for abortion. If they have multiple risk factors and are determined to be high risk for VTE and are not currently on VTE prophylaxis, they can be offered anticoagulation prior to the abortion if there is a delay until the procedure, or can forego pre-procedure anticoagulation. High risk individuals can be offered 4-6 weeks of anticoagulation post procedure.

Additional considerations

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and ketorolac, are generally recommended as safe and effective options for post-operative pain. NSAIDs are alternatives to opioid medication without any significant associations with increased post-operative bleeding, development of hematomas, or increased complications.

NSAIDs inhibit platelet cyclooxygenase and block the formation thromboxane A2 which is involved in platelet aggregation. The effects of non-aspirin NSAIDs are reversible and function of the platelets are restored once the drugs are cleared from circulation. Platelet function returns to normal within 12 hours after ibuprofen administration.

In individuals on anticoagulation or with coagulopathies, use of NSAIDs should be carefully assessed and tailored on an individual basis. Most NSAIDs can enhance the activity of oral anticoagulants, such as warfarin, apixaban, rivaroxaban, or clopidogrel, and potentially result in increased bleeding risk. Use of NSAIDs for post-abortion pain management is generally recommended; however, NSAID use should be tailored to the risks and benefits for the specific individual with a bleeding disorder or on anticoagulation, with specific attention paid to the possible interaction of NSAIDs with anticoagulants.

What treatment to prefer:

Individuals with bleeding disorders or on anticoagulation diagnosed with early pregnancy loss, including incomplete abortion, should be offered surgical management given the lower and more predictable blood loss with this management option as compared to expectant or medical management.

Clinical recommendations

The following recommendations are based primarily on consensus and expert opinion:

• For first-trimester abortion, surgical management is generally preferred over medical management for individuals with bleeding disorders or who are on anticoagulation. For secondtrimester abortion, surgical management may be recommended to limit bleeding though this has not been studied in these populations. Providers should individualize the mode of abortion with the approach of shared decision making, interdisciplinary collaboration, and accounting for the availability of procedural abortion and resources if complications
• In an individual who presents for second-trimester procedural abortion with a suspected bleeding disorder, prompt referral to a hematologist should be initiated
• Decision on the ideal setting for individuals undergoing procedural abortion with bleeding disorders or who are on anticoagulation should be individualized. Given the low bleeding risk of first-trimester procedures, it is possible to manage individuals without additional risk factors for bleeding in a hospital outpatient clinic or free-standing clinic setting. In general, second trimester abortions in these individuals should be preferably done in a hospital-based setting given increased access to resources should complications or hemorrhage occur.
• Although data concerning bleeding risk is limited, for a first trimester procedural abortion in an individual on anticoagulation who has no additional risk factors for bleeding and is to undergo a procedure that is anticipated to be uncomplicated, anticoagulation can generally continue uninterrupted.
• All individuals should undergo an individualized risk assessment for VTE when they present for abortion. If they have multiple risk factors and are determined to be high risk for VTE and are not currently on VTE prophylaxis, they can be offered anticoagulation prior to the abortion if there is a delay until the procedure, or can forego preprocedure anticoagulation. High risk individuals can be offered 4-6 weeks of anticoagulation post procedure.
• The decision to interrupt anticoagulation in an individual currently on anticoagulation desiring a second-trimester procedural abortion must be done after an individualized risk assessment including absolute risk of VTE if anticoagulation is to be interrupted and bleeding risks with anticoagulation if it is continued.
• Use of NSAIDs for post-abortion pain management is generally recommended; however, NSAID use should be tailored to the risks and benefits for the specific individual with a bleeding disorder or on anticoagulation, with specific attention paid to the possible interaction of NSAIDs with anticoagulants.
• Surgical management of incomplete abortion in individuals with bleeding disorders or on anticoagulation is generally recommended over medical management

Source: J.K. Lee, A.B. Zimrin and C. Sufrin; Contraception 104 (2021) 119–127

https://doi.org/10.1016/j.contraception.2021.03.016