Table 3. Recommendations of VTE... | American Society of Hematology

Table 3.

Recommendations of VTE management in pregnancy across major clinical practice guidelines

Characteristic	ASH 2018¹³	RCOG 2015⁵²	SOGC 2014¹⁸	ACCP 2012¹⁵	ANZJOG 2012¹⁷
Once- vs twice-daily LMWH	For pregnant women with acute VTE treated with LMWH, the ASH guideline panel suggests either once-per-day or twice-per-day dosing regimens (conditional recommendation, very low certainty in evidence about effects).	LMWH should be given in doses titrated against the woman's booking or early pregnancy weight. There is insufficient evidence to recommend whether the dose of LMWH should be given once daily or in two divided doses (grade C).	For the treatment of acute VTE in pregnancy, we recommend adhering to the manufacturer's recommended dosing for individual LMWH based on the woman's current weight. (II-1A). LMWH can be administered once or twice a day depending on the agent selected (III-C).	No recommendation	Treatment of acute VTE in pregnancy should be with LMWH given once daily or twice daily at therapeutic doses. There is currently insufficient evidence to favor one dose regimen over the other (group consensus level 1). Women with PE or more extensive DVT (ie, iliofemoral thrombosis) during pregnancy should receive initial treatment with twice-daily LMWH for at least 8 to 12 weeks, after which time a reduction to a once-daily regimen may be considered (group consensus level 2).
Anti-Xa level monitoring	For pregnant women receiving therapeutic-dose LMWH for the treatment of VTE, the ASH guideline panel suggests against routine monitoring of anti-FXa levels to guide dosing (conditional recommendation, low certainty in evidence about effects).	Routine measurement of peak anti-Xa activity for patients taking LMWH for treatment of acute VTE in pregnancy or postpartum is not recommended except in women at extremes of body weight (<50 and 90 kg or more) or with other complicating factors (eg, with renal impairment or recurrent VTE) (grade C).	No recommendation In the text: consideration should be given to initial monitoring of anti-Xa activity, during the first month of treatment only, to target a level of 0.6 to 1.0 U/mL 4 hours after injection, bearing in mind that target levels will vary with the LMWH used. However, the cost of the assay, the lack of correlation with clinical events, and the variability between assays make the utility of monitoring anti-FXa activity in pregnancy controversial.	No recommendation In the text: Given the absence of large studies using clinical end points that demonstrate an optimal therapeutic anti-Xa LMWH range or that dose adjustments increase the safety or efficacy of therapy, the lack of accuracy and reliability of the measurement, the lack of correlation with risk of bleeding and recurrence, and the cost of the assay, routine monitoring with anti-Xa levels is difficult to justify.	There is insufficient evidence to recommend monitoring of anti-Xa levels to guide dosing in women on therapeutic dose LMWH (group consensus level 1).
Peripartum anticoagulation management	For pregnant women receiving therapeutic-dose LMWH for the management of VTE, the ASH guideline panel suggests scheduled delivery with prior discontinuation of anticoagulant therapy (conditional recommendation, very low certainty in evidence about effects). For pregnant women receiving prophylactic-dose LMWH, the ASH guideline panel suggests against scheduled delivery with discontinuation of prophylactic anticoagulation compared with allowing spontaneous labor (conditional recommendation, very low certainty in evidence about effects).	The woman taking LMWH for maintenance therapy should be advised that once she is in established labor or thinks that she is in labor, she should not inject any further heparin. When VTE occurs at term, consideration should be given to the use of intravenous UFH, which is more easily manipulated (grade D). Where delivery is planned, either by elective cesarean section or induction of labor, LMWH maintenance therapy should be discontinued 24 hours prior to planned delivery (grade D).	Women receiving prophylactic, intermediate-dose, or therapeutic anticoagulation should have a discussion about options for analgesia/anesthesia prior to delivery (III-B). Switching from thromboprophylactic LMWH to a prophylactic dose of UFH at term (37 weeks) may be considered to allow for more options with respect to labor analgesia (III-L). Discontinue prophylactic or intermediate-dose LMWH or UFH upon the onset of spontaneous labor or the day before a planned induction of labor or cesarean section (II-3B).	For pregnant women receiving adjusted-dose LMWH therapy and where delivery is planned, we recommend discontinuation of LMWH at least 24 hours prior to induction of labor or cesarean section (or expected time of neuraxial anesthesia) rather than continuing LMWH up until the time of delivery (grade 1B).	No recommendation
Time of neuraxial anesthesia after last dose of LMWH		Regional anesthetic or analgesic techniques should not be undertaken until at least 24 hours after the last dose of therapeutic LMWH (grade D).	For women taking LMWH, neuraxial anesthesia can be administered as a: (a) Prophylactic dose: a minimum of 10 to 12 hours after the last dose (III-B) (b) Therapeutic dose: after 24 hours since the last dose (III-B) Neuraxial anesthesia must be avoided in a woman who is fully anticoagulated or in whom there is evidence of altered coagulation (II-3A).	For pregnant women receiving adjusted-dose LMWH therapy and where delivery is planned, we recommend discontinuation of LMWH at least 24 hours prior to induction of labor or cesarean section (or expected time of neuraxial anesthesia) rather than continuing LMWH up until the time of delivery (grade 1B).	Table 3: LMWH—prophylactic dose: ensure a minimum of 12 hours after LMWH dose before the performance of a neuraxial block or removal of a neuraxial catheter. LMWH—therapeutic dose: preferable to avoid therapeutic dosing with catheter in situ; wait at least 24 hours after the last dose of LMWH before performing neuraxial blockade or removing a neuraxial catheter.

Characteristic	ASH 2018¹³	RCOG 2015⁵²	SOGC 2014¹⁸	ACCP 2012¹⁵	ANZJOG 2012¹⁷
Once- vs twice-daily LMWH	For pregnant women with acute VTE treated with LMWH, the ASH guideline panel suggests either once-per-day or twice-per-day dosing regimens (conditional recommendation, very low certainty in evidence about effects).	LMWH should be given in doses titrated against the woman's booking or early pregnancy weight. There is insufficient evidence to recommend whether the dose of LMWH should be given once daily or in two divided doses (grade C).	For the treatment of acute VTE in pregnancy, we recommend adhering to the manufacturer's recommended dosing for individual LMWH based on the woman's current weight. (II-1A). LMWH can be administered once or twice a day depending on the agent selected (III-C).	No recommendation	Treatment of acute VTE in pregnancy should be with LMWH given once daily or twice daily at therapeutic doses. There is currently insufficient evidence to favor one dose regimen over the other (group consensus level 1). Women with PE or more extensive DVT (ie, iliofemoral thrombosis) during pregnancy should receive initial treatment with twice-daily LMWH for at least 8 to 12 weeks, after which time a reduction to a once-daily regimen may be considered (group consensus level 2).
Anti-Xa level monitoring	For pregnant women receiving therapeutic-dose LMWH for the treatment of VTE, the ASH guideline panel suggests against routine monitoring of anti-FXa levels to guide dosing (conditional recommendation, low certainty in evidence about effects).	Routine measurement of peak anti-Xa activity for patients taking LMWH for treatment of acute VTE in pregnancy or postpartum is not recommended except in women at extremes of body weight (<50 and 90 kg or more) or with other complicating factors (eg, with renal impairment or recurrent VTE) (grade C).	No recommendation In the text: consideration should be given to initial monitoring of anti-Xa activity, during the first month of treatment only, to target a level of 0.6 to 1.0 U/mL 4 hours after injection, bearing in mind that target levels will vary with the LMWH used. However, the cost of the assay, the lack of correlation with clinical events, and the variability between assays make the utility of monitoring anti-FXa activity in pregnancy controversial.	No recommendation In the text: Given the absence of large studies using clinical end points that demonstrate an optimal therapeutic anti-Xa LMWH range or that dose adjustments increase the safety or efficacy of therapy, the lack of accuracy and reliability of the measurement, the lack of correlation with risk of bleeding and recurrence, and the cost of the assay, routine monitoring with anti-Xa levels is difficult to justify.	There is insufficient evidence to recommend monitoring of anti-Xa levels to guide dosing in women on therapeutic dose LMWH (group consensus level 1).
Peripartum anticoagulation management	For pregnant women receiving therapeutic-dose LMWH for the management of VTE, the ASH guideline panel suggests scheduled delivery with prior discontinuation of anticoagulant therapy (conditional recommendation, very low certainty in evidence about effects). For pregnant women receiving prophylactic-dose LMWH, the ASH guideline panel suggests against scheduled delivery with discontinuation of prophylactic anticoagulation compared with allowing spontaneous labor (conditional recommendation, very low certainty in evidence about effects).	The woman taking LMWH for maintenance therapy should be advised that once she is in established labor or thinks that she is in labor, she should not inject any further heparin. When VTE occurs at term, consideration should be given to the use of intravenous UFH, which is more easily manipulated (grade D). Where delivery is planned, either by elective cesarean section or induction of labor, LMWH maintenance therapy should be discontinued 24 hours prior to planned delivery (grade D).	Women receiving prophylactic, intermediate-dose, or therapeutic anticoagulation should have a discussion about options for analgesia/anesthesia prior to delivery (III-B). Switching from thromboprophylactic LMWH to a prophylactic dose of UFH at term (37 weeks) may be considered to allow for more options with respect to labor analgesia (III-L). Discontinue prophylactic or intermediate-dose LMWH or UFH upon the onset of spontaneous labor or the day before a planned induction of labor or cesarean section (II-3B).	For pregnant women receiving adjusted-dose LMWH therapy and where delivery is planned, we recommend discontinuation of LMWH at least 24 hours prior to induction of labor or cesarean section (or expected time of neuraxial anesthesia) rather than continuing LMWH up until the time of delivery (grade 1B).	No recommendation
Time of neuraxial anesthesia after last dose of LMWH		Regional anesthetic or analgesic techniques should not be undertaken until at least 24 hours after the last dose of therapeutic LMWH (grade D).	For women taking LMWH, neuraxial anesthesia can be administered as a: (a) Prophylactic dose: a minimum of 10 to 12 hours after the last dose (III-B) (b) Therapeutic dose: after 24 hours since the last dose (III-B) Neuraxial anesthesia must be avoided in a woman who is fully anticoagulated or in whom there is evidence of altered coagulation (II-3A).	For pregnant women receiving adjusted-dose LMWH therapy and where delivery is planned, we recommend discontinuation of LMWH at least 24 hours prior to induction of labor or cesarean section (or expected time of neuraxial anesthesia) rather than continuing LMWH up until the time of delivery (grade 1B).	Table 3: LMWH—prophylactic dose: ensure a minimum of 12 hours after LMWH dose before the performance of a neuraxial block or removal of a neuraxial catheter. LMWH—therapeutic dose: preferable to avoid therapeutic dosing with catheter in situ; wait at least 24 hours after the last dose of LMWH before performing neuraxial blockade or removing a neuraxial catheter.

See Table 1 for descriptions used for evidence grading and consensus.