Neuraxial Analgesia in the Anticoagulated Parturient

Abstract

Anticoagulants are administered during pregnancy and postpartum to treat or prevent thrombotic events. For two decades, this practice has been supported by numerous studies, clinical evaluation, and diagnostic scoring of the peri- and postpartum thrombotic risk. Guidelines have since emerged to manage its treatment and prevention [1–4]. However, gaps persist in our knowledge of the condition, and there is evidence that anticoagulants can be more precisely monitored and targeted according to the individual risk [5]. Multidisciplinary management of the peripartum period aims to prevent both hemorrhagic and thrombotic risks, to avoid epidural hematoma, an unusual but severe complication of regional analgesia, as well as severe postpartum hemorrhage, and the occurrence or recurrence of a thrombotic event [6]. Managing analgesia during labor and delivery is a complex challenge due to the unique pharmacokinetic characteristics of drugs at the end of pregnancy and the unpredictability of spontaneous labor [6, 7]. A thorough multidisciplinary protocol should detail the neuraxial labor analgesia management during the peripartum period in these patients.

Appendix

19.1.1 Guidelines for Thromboprophylaxis and Antithrombotic Treatment During Pregnancy and the Postpartum Period

Antithrombotic prophylaxis and anticoagulant treatment are prescribed during the peri- and postpartum periods to prevent venous, arterial, or placental thrombosis occurrence and recurrence. In low risk patients with no familial or individual history of previous thrombosis, the venous thrombosis incidence is low during all three trimesters at 1–2 per 1,000, increasing only during the postpartum [1, 2, 21, 22, 36, 37]. Perinatal practitioners are particularly concerned with detecting any risk factor that may justify thromboprophylaxis [1, 2].

Thrombosis risk factors are detailed in the 2012 ACCP guidelines [1]:

• Patients at extreme risk or those with special conditions require multidisciplinary preconception and pregnancy management. Relevant conditions include: antiphospholipid syndrome with antiprothrombinase, myelproliferative disorders, Budd Chiari disease or digestive venous thrombosis, inflammatory systemic disease, antithrombin deficiency, known complex thrombophilia, and pulmonary hypertension.

• High-risk conditions include: previous pulmonary embolism, previous proximal idiopathic DVT, previous contraceptive, pregnancy, or postpartum (estrogenic) induced proximal DVT, proximal DVT within the previous 2 years, and current long-term anticoagulation therapy.

• The intermediate risk conditions are: non-idiopathic or non-estrogenic DVT at least 2 years previously, distal estrogenic DVT, and previous estrogenic or cerebral vein thrombosis.

• Low risk conditions include: previous recurrent superficial vein thrombosis and/or major venous insufficiency, previous non-estrogenic distal DVT, previous ovarian DVT, previous non-estrogenic cerebral vein thrombosis, and previous familial DVT before age 45 years in an immediate relative.

Concurrent risk factors increase the final risk level. If two or more of the following additional risk factors are present, then the risk level category increases: aged over 35 years, multiparity, long distance travel, BMI >30 kg/m² before pregnancy, prolonged bed rest, medical assisted procreation, previous severe placental vascular disease, multiple pregnancies, major venous insufficiency, protein C or protein S deficiency, and heterozygous and homozygous factor V Leiden (FVL) or prothrombin mutation (PTG20210A). The following additional risk factors increase the postpartum final risk level: Cesarean section, severe postpartum hemorrhage, and severe preeclampsia [21, 22, 36–38].

Evaluation scores have been devised to detect excessive thrombotic risk and guide the thromboprophylaxis regimen based on antithrombotic or anticoagulant treatments available during pregnancy and postpartum [38, 39]. Screening for thrombophilia can be performed in the clinical risk evaluation and may reveal additional risk in the form of genetic polymorphisms [1, 40].

The thromboprophylaxis regimen should be tailored according to the evaluated risk level.

General principles for thromboprophylaxis in pregnant and postpartum patients include the following:

• Contention socks are always recommended throughout pregnancy and the postpartum period.

• Low Molecular Weight Heparin (LMWH) recommended for thrombosis prevention and cure; its safety and efficiency have been validated in large cohort series [1, 2, 33–35].

• The LMWH or UFH dose must be tailored according to the patient weight in classes of <50, 50–100, 100–130, and >130 kg [1, 25].

• The LMWH or UFH dose must be monitored and increased to counteract inflammatory syndrome occurring at the end of pregnancy [26–28].

• The LMWH pharmacokinetics allows once daily administration during pregnancy and postpartum except in obese patients [28, 41].

• Peripartum therapeutic management is easier when a half dose is administered twice daily 1 week before delivery [1].

• Postpartum hemostasis changes are maximal during the first 3 days and persist for 6–8 weeks following delivery.

Targeted thromboprophylaxis can be performed as follows [1]:

• Low risk patient: Postpartum LMWH at 50–60 IU kg⁻¹ daily immediately after delivery for 6 weeks.

• Intermediate risk patient: Pregnancy and postpartum LMWH at 50–60 IU kg⁻¹ daily from pregnancy diagnosis, until delivery, and continued an additional 6 weeks.

• High-risk patient: Pregnancy and postpartum prevention or treatment [1, 2] with LMWH at 100–200 IU kg⁻¹ daily from pregnancy diagnosis, until delivery, and continued an additional 6 weeks.

The platelet count should be monitored twice weekly for the 3 first weeks of therapy and then once monthly. Monitor clinical safety using aPTT or anti-Xa activity.

Key Messages

• Anticoagulants are currently used to prevent or treat pregnancy and postpartum related thrombosis (Appendix)

• The anticoagulated parturient has an increased risk of hemorrhage after delivery

• Anticoagulation in the obstetric context seems to have a lower risk of epidural hematoma after neuraxial anesthesia or analgesia compared to other non-obstetric patients

• For a safe delivery, anticoagulants must be discontinued at least when first stage of labor begins

• Neuraxial analgesia setting may respect the optimal delay of two and half times the drug elimination half-life after anticoagulation stop

• The management of the anticoagulated parturient requires a multidisciplinary approach and individual assessment of the hemorrhage and thrombosis risk balance.