How long should fraxiparine (nadroparin) be stopped before a cesarean section in a pregnant patient?

Timing of Fraxiparine Discontinuation Before Cesarean Section

Fraxiparine (nadroparin) should be discontinued at least 24 hours prior to a planned cesarean section to minimize bleeding risk and allow safe neuraxial anesthesia. 1

Evidence-Based Timing Recommendations

Standard Guideline Recommendation

• The American College of Chest Physicians strongly recommends discontinuing LMWH at least 24 hours prior to induction of labor or cesarean section (Grade 1B). 1 This timing applies specifically to women receiving adjusted-dose LMWH therapy and is critical for safe placement of neuraxial anesthesia (epidural or spinal). 1

• The American Society of Hematology 2018 guidelines reinforce this 24-hour minimum interval, emphasizing that this window allows adequate clearance of anticoagulant effect to reduce bleeding complications during surgery and permit safe epidural placement. 1

Supporting Clinical Data

• Observational studies demonstrate that women who delivered within 24 hours of their last heparin injection had prolonged aPTT values at delivery, increasing bleeding risk. 2 In one series, 6 of 11 women (55%) receiving subcutaneous heparin delivered with prolonged aPTT when the interval was less than 24 hours. 2

• A retrospective study of different nadroparin regimens showed that pre-operative administration of nadroparin 5700 IU significantly increased bleeding complications requiring either conservative treatment or re-laparotomy (19/574 women, 3.3%) compared to postoperative-only dosing (1/306 women, 0.3%; p=0.005). 3

Coordination with Anesthesia

• The exact timing should be coordinated with the obstetrics and anesthesia teams, as intravenous heparin (if used) should be stopped at least 6 hours before delivery to allow safe epidural placement. 1 While this refers to UFH, the principle of coordinating with anesthesia applies equally to LMWH.

• For women on therapeutic-dose LMWH, consultation with a high-risk obstetrician and obstetric anesthesiologist is specifically recommended regarding optimal timing of discontinuation in preparation for epidural anesthesia. 1

Practical Implementation Algorithm

For Planned Cesarean Section:

1. Stop fraxiparine 24 hours before scheduled surgery time 1
2. Verify adequate time interval with anesthesia team before neuraxial block placement 1
3. Resume LMWH postoperatively when hemostasis is assured (typically 6-12 hours post-cesarean for prophylactic dosing, longer for therapeutic dosing) 3

For Spontaneous Labor:

1. Instruct patient to stop fraxiparine immediately at onset of labor or membrane rupture 2
2. Check aPTT if delivery occurs within 24 hours of last dose 2
3. Consider protamine sulfate reversal if emergency cesarean is needed with recent LMWH administration 2

Critical Caveats

• The 24-hour minimum is non-negotiable for planned procedures. Women delivering within 28 hours of their last heparin injection are at risk for prolonged anticoagulation at delivery. 2

• Prophylactic-dose nadroparin (2850 IU) administered postoperatively only (not pre-operatively) significantly reduces bleeding complications compared to pre- and post-operative dosing. 3 This supports avoiding pre-operative LMWH administration when cesarean section is planned.

• For women on therapeutic anticoagulation for acute VTE, the risk-benefit calculation differs, but the 24-hour discontinuation window before planned delivery remains standard. 1