Clinical Commander

Back to dossier
cardio.dvt.pregnancy.v1PRODUCTION
cardio.dvt.pregnancy.v1

DVT during pregnancy / postpartum

cardiologyacuteadultpregnancy
Hard-required inputs
0 / 8
Care setting:

Encounter flow

11/12 authored

Canonical 12-phase frame with authored status for this dossier.

Current phase

Frame

Detailed

DVT in pregnancy = LMWH-only paradigm (NO DOAC, NO warfarin antepartum); >80% left-sided iliofemoral due to mechanical compression; gravid uterus + hypercoagulable state; postpartum window 0-6 wk is highest VTE risk; coordinate with MFM + OB throughout

Inputs
2
Actions
0
Advance rule
Set
Advance when

pregnancy confirmed and gestational age established

Patient inputs (12)

Drives risk-benefit (warfarin embryopathy 6-12 wk; delivery planning >34 wk; postpartum window 0-6 wk highest VTE risk)

Multiparity adds VTE risk; informs counseling for future pregnancies

Prior VTE = strong indication for prophylactic or therapeutic LMWH throughout pregnancy + postpartum (RCOG 37a)

Confirms pregnancy status — drives entire treatment paradigm (LMWH only, NO DOAC, NO warfarin antepartum)

First-line diagnostic imaging in pregnancy DVT (ASH 2018; RCOG 37a) — femoral + popliteal; pelvic vein limited but informs MRV need

Baseline platelets + Hgb for HIT screen + bleeding risk; pregnancy anemia common (dilutional) requires baseline

Postpartum AC choice depends — LMWH and warfarin compatible with breastfeeding; DOAC NOT recommended (LactMed)

Pregnancy increases GFR by 50%; LMWH dosing weight-based but anti-Xa monitoring useful at extremes; CKD-EPI not validated in pregnancy

MRV (without gadolinium) for suspected iliac / pelvic vein DVT not visualized on compression US; gadolinium AVOIDED in pregnancy (Cat C; crosses placenta)

Antithrombin deficiency, APS, homozygous Factor V Leiden modify dose intensity (RCOG 37a)

LFT baseline before LMWH (rare hepatotoxicity); pregnancy-related liver disease (HELLP, AFLP) excluded

Scheduled C-section vs spontaneous labor changes LMWH hold strategy; neuraxial anesthesia requires ≥24 h LMWH hold

* = hard-required. Engine cannot meaningfully run until these are filled.

Severity triggers (6)

6 need judgement
  • informationallife_threateningperipartum_bleeding_on_anticoagulation
    Active vaginal bleeding, postpartum hemorrhage, or hematoma in pregnant or peripartum patient on therapeutic LMWH or UFH
    Trigger could not be auto-evaluated — needs clinician judgement.
  • informationallife_threateningphlegmasia_cerulea_dolens_in_pregnancy
    Limb-threatening iliofemoral DVT in pregnant patient — limb + pregnancy emergency; CDT in pregnancy is limited-data, case-by-case
    Trigger could not be auto-evaluated — needs clinician judgement.
  • informationallife_threateningconcurrent_pe_in_pregnancy
    Pregnant DVT patient develops dyspnea, pleuritic chest pain, hypoxemia, syncope — concurrent PE confirmed by CT-PA (fetal dose <0.1 mGy acceptable per ACR) or V/Q (lower fetal dose alternative)
    Trigger could not be auto-evaluated — needs clinician judgement.
  • informationalseverepostpartum_thrombosis_recurrence
    New DVT or PE during the 6-wk postpartum window despite therapeutic LMWH — heparin failure or escalation indication
    Trigger could not be auto-evaluated — needs clinician judgement.
  • informationalseveredoac_misuse_or_pregnancy_exposure
    Pregnancy discovered while on DOAC OR DOAC inadvertently prescribed antepartum — pregnancy exposure with limited safety data
    Trigger could not be auto-evaluated — needs clinician judgement.
  • informationalmoderateivc_filter_retrieval_timing_in_pregnancy
    Pregnant patient with IVC filter placed for absolute AC contraindication — retrieval planning peripartum vs postpartum
    Trigger could not be auto-evaluated — needs clinician judgement.

Workflow calculators

Run this disease's risk and dosing calculators inline.

ENTRYrequiredDrives risk stratification
Loading…

Recommended regimen

Pregnancy DVT — LMWH antepartum + 6-wk postpartum (ASH 2018 + RCOG 37a)
axis: pregnancy_dvt_lmwh_paradigm_with_delivery_planning
Selected axis "Pregnancy DVT — LMWH antepartum + 6-wk postpartum (ASH 2018 + RCOG 37a)" by default fallback (first axis)
  • enoxaparin
    first line
    lmwh
    1 mg/kg SC q12h (weight-based; titrate q4 wk as pregnancy weight increases) • SC • q12h throughout pregnancy + ≥6 wk postpartum
    triggers: confirmed_dvt_in_pregnancy, no_active_bleed, platelets_above_50
    ASH 2018 (Bates PMID 30482767) Class I; RCOG Green-top 37a; LMWH does NOT cross placenta; preferred over UFH due to less HIT, osteoporosis, and easier dosing
    rxcui 67108
  • dalteparin
    first line
    lmwh
    200 IU/kg SC daily OR 100 IU/kg SC BID • SC • daily or BID
    triggers: enoxaparin_unavailable, cost_constraint
    ASH 2018; alternative LMWH; same safety profile in pregnancy
    rxcui 67109
  • heparin
    second line
    unfractionated_heparin
    80 U/kg bolus + 18 U/kg/h infusion targeting aPTT 1.5-2.5× • IV • continuous
    triggers: delivery_imminent_within_24h, severe_renal_impairment_crcl_below_30, anticipated_invasive_procedure
    ASH 2018; UFH preferred when reversibility needed (rapid onset/offset, protamine reversible); transitions in late 3rd trimester common
    rxcui 235473
  • warfarin
    comorbidity specific
    vitamin_k_antagonist
    POSTPARTUM ONLY: 5 mg PO daily; INR target 2-3 with overlapping LMWH × ≥5 d AND until INR ≥2 for ≥24 h • PO • daily; INR-driven
    triggers: postpartum_period, breastfeeding_acceptable_per_lactmed, no_pregnancy
    CONTRAINDICATED antepartum (warfarin embryopathy 6-12 wk; CNS bleeding any trimester; fetal hemorrhage at delivery); compatible with breastfeeding (does not appear in clinically significant amounts in milk per LactMed)
    rxcui 11289
  • apixaban
    contraindication substitute
    doac_factor_xa_direct
    AVOID in pregnancy AND breastfeeding • PO • avoided
    triggers: contraindicated_pregnancy, contraindicated_breastfeeding
    AMPLIFY (Agnelli NEJM 2013) and all DOAC trials EXCLUDED pregnancy; DOACs cross placenta; limited breastfeeding data shows drug detected in milk; LMWH or warfarin preferred postpartum
    rxcui 1364430

outpatient playbook — drug actions (3)

  1. 1. STOP AC at 6 wk postpartum if pregnancy was the only provoking factor
    discontinue at 6 wk postpartum • n/a • n/a
    trigger: Pregnancy-only provoked DVT, no thrombophilia, no recurrent VTE history
    ASH 2018; ACCP 2021 — pregnancy is transient major risk; minimum 3 mo total AC, 6-wk postpartum minimum
  2. 2. continue extended LMWH or transition to warfarin if unprovoked or thrombophilia
    rxcui 67108
    enoxaparin 1 mg/kg SC BID OR warfarin 5 mg daily INR 2-3 • SC or PO • BID or daily
    trigger: Unprovoked DVT, APS, antithrombin deficiency, recurrent VTE
    ASH 2020 PMID 33007077; extended therapy for persistent risk
  3. 3. apixaban acceptable if NOT breastfeeding and long-term AC needed
    rxcui 1364430
    apixaban 5 mg BID full or 2.5 mg BID extended-reduced • PO • BID
    trigger: Postpartum non-breastfeeding + long-term AC + DOAC preference
    AMPLIFY / AMPLIFY-EXT once breastfeeding stopped

Auto-drafted A&P note

outpatient

Subjective

- Possible entry pathways: Pregnant patient with left leg swelling, calf pain, or whole-leg edema (>80% of pregnancy DVT is left-sided due to right common iliac artery compression of left common iliac vein); Compression US confirms iliofemoral DVT in pregnant patient — initiate LMWH immediately; MRV if pelvic vein extension suspected; Postpartum (within 6 weeks) calf pain, swelling, or PE symptoms — postpartum is the highest-risk window for VTE (~5× pregnancy risk).

Objective

- No vitals, labs, or imaging entered for this encounter.

Assessment

**DVT during pregnancy / postpartum** (cardio.dvt.pregnancy.v1).
Scope: DVT in pregnancy = LMWH-only paradigm (NO DOAC, NO warfarin antepartum); >80% left-sided iliofemoral due to mechanical compression; gravid uterus + hypercoagulable state; postpartum window 0-6 wk is highest VTE risk; coordinate with MFM + OB throughout

No severity triggers fired against current inputs.

Plan

Regimen axis: **Pregnancy DVT — LMWH antepartum + 6-wk postpartum (ASH 2018 + RCOG 37a)**.
1. enoxaparin 1 mg/kg SC q12h (weight-based; titrate q4 wk as pregnancy weight increases) SC q12h throughout pregnancy + ≥6 wk postpartum (lmwh, first line) — ASH 2018 (Bates PMID 30482767) Class I; RCOG Green-top 37a; LMWH does NOT cross placenta; preferred over UFH due to less HIT, osteoporosis, and easier dosing
2. dalteparin 200 IU/kg SC daily OR 100 IU/kg SC BID SC daily or BID (lmwh, first line) — ASH 2018; alternative LMWH; same safety profile in pregnancy
3. heparin 80 U/kg bolus + 18 U/kg/h infusion targeting aPTT 1.5-2.5× IV continuous (unfractionated_heparin, second line) — ASH 2018; UFH preferred when reversibility needed (rapid onset/offset, protamine reversible); transitions in late 3rd trimester common
4. warfarin POSTPARTUM ONLY: 5 mg PO daily; INR target 2-3 with overlapping LMWH × ≥5 d AND until INR ≥2 for ≥24 h PO daily; INR-driven (vitamin_k_antagonist, comorbidity specific) — CONTRAINDICATED antepartum (warfarin embryopathy 6-12 wk; CNS bleeding any trimester; fetal hemorrhage at delivery); compatible with breastfeeding (does not appear in clinically significant amounts in milk per LactMed)
5. apixaban AVOID in pregnancy AND breastfeeding PO avoided (doac_factor_xa_direct, contraindication substitute) — AMPLIFY (Agnelli NEJM 2013) and all DOAC trials EXCLUDED pregnancy; DOACs cross placenta; limited breastfeeding data shows drug detected in milk; LMWH or warfarin preferred postpartum

Setting playbook (outpatient) — Long-term postpartum management; future pregnancy planning; recurrent VTE prevention; address modifiable factors
6. STOP AC at 6 wk postpartum if pregnancy was the only provoking factor discontinue at 6 wk postpartum n/a n/a — Pregnancy-only provoked DVT, no thrombophilia, no recurrent VTE history (ASH 2018; ACCP 2021 — pregnancy is transient major risk; minimum 3 mo total AC, 6-wk postpartum minimum)
7. continue extended LMWH or transition to warfarin if unprovoked or thrombophilia enoxaparin 1 mg/kg SC BID OR warfarin 5 mg daily INR 2-3 SC or PO BID or daily — Unprovoked DVT, APS, antithrombin deficiency, recurrent VTE (ASH 2020 PMID 33007077; extended therapy for persistent risk)
8. apixaban acceptable if NOT breastfeeding and long-term AC needed apixaban 5 mg BID full or 2.5 mg BID extended-reduced PO BID — Postpartum non-breastfeeding + long-term AC + DOAC preference (AMPLIFY / AMPLIFY-EXT once breastfeeding stopped)

Non-pharmacologic actions:
- Compression stocking only if symptomatic PTS
- Address modifiable VTE risk factors (smoking, weight, hormones)
- Avoid combined OCP
- Document future pregnancy thromboprophylaxis plan: prophylactic LMWH throughout next pregnancy + 6-wk postpartum if prior VTE; therapeutic if unprovoked or thrombophilia

AVOID / contraindication checks:
- Warfarin_avoid_antepartum_embryopathy_6_12wk_cns_bleed_any_trimester (FDA Cat X / X)
- Doac_avoid_pregnancy_no_safety_data_crosses_placenta (ASH 2018; FDA pregnancy categories)
- Doac_avoid_breastfeeding_drug_detected_in_milk (LactMed)
- Gadolinium_avoid_pregnancy_for_mrv_use_non_contrast (ACR)
- Lmwh_dose_adjust_weekly_in_pregnancy_as_weight_changes (ASH 2018)
- Hold_lmwh_24h_pre_scheduled_delivery_or_neuraxial_anesthesia (ASRA + ASH 2018)
- Hold_lmwh_12h_pre_scheduled_delivery_for_prophylactic_dose (ASRA)
- Decision:resume_lmwh_6_12h_postpartum_if_hemostasis_adequate_or_12_24h_post_csection (RCOG 37a)
- Decision:postpartum_ac_minimum_6_weeks (ASH 2018)

Monitoring

Regimen monitoring:
- anti xa peak 4h post dose target 0.6 1.0 iu ml at extreme weight or renal (ASH 2018)
- cbc weekly first 2 wk then monthly for hit screen (ASH 2018)
- platelets q3 5d first 2 wk lmwh for hit (ASH 2018)
- weight check q4 wk in pregnancy for dose adjustment
- inr q4 weeks warfarin steady state postpartum (ACCP 2021)
- creatinine q3mo per pregnancy physiology
- coordinate lmwh hold 24h pre delivery with obstetric team (ASRA + RCOG 37a)
- plan postpartum ac at least 6 weeks (ASH 2018)

Setting (outpatient) monitoring:
- Annual PTS + bleed assessment
- Annual labs
- Pregnancy plan reassessment

Follow-up plan: Postpartum 6 wk LMWH minimum; transition to warfarin or continue LMWH per patient preference + breastfeeding (DOAC NOT recommended in lactation); contraception counseling (avoid combined OCP — OCP increases VTE risk 3-6×; progestin-only or non-hormonal preferred); future pregnancy thromboprophylaxis plan documented
- Close-out criterion: 6-wk postpartum AC + contraception + future pregnancy plan finalized

Monitoring phase: Anti-Xa level (peak 0.6-1.0 IU/mL for BID dosing) at 4 h post-dose at extremes of weight or renal impairment; CBC weekly first 2 wk for HIT screen; weight-based dose adjustment q4 wk through pregnancy as weight increases; coordinate delivery LMWH hold ≥24 h before scheduled / 12 h prophylactic dose

Disposition

Current setting: outpatient — Long-term postpartum management; future pregnancy planning; recurrent VTE prevention; address modifiable factors

Disposition criteria:
- Long-term hematology / vascular follow-up; lifelong if extended AC indicated

Escalation triggers (move to higher acuity):
- New pregnancy → restart prophylactic LMWH per RCOG 37a
- New VTE → evaluate APS / cancer / thrombophilia; resume indefinite AC
- Major bleed on extended AC → reassess risk-benefit

Earlier-Return Triggers

Return-precaution thresholds (watch for):
- [LIFE_THREATENING] Active vaginal bleeding, postpartum hemorrhage, or hematoma in pregnant or peripartum patient on therapeutic LMWH or UFH
- [LIFE_THREATENING] Limb-threatening iliofemoral DVT in pregnant patient — limb + pregnancy emergency; CDT in pregnancy is limited-data, case-by-case
- [LIFE_THREATENING] Pregnant DVT patient develops dyspnea, pleuritic chest pain, hypoxemia, syncope — concurrent PE confirmed by CT-PA (fetal dose <0.1 mGy acceptable per ACR) or V/Q (lower fetal dose alternative)

Citations

- ASH 2018 VTE in Pregnancy + ACCP/CHEST 2018 / 2021 + RCOG Green-top 37a + ACOG Practice Bulletin 196 [PMID:30482767](https://pubmed.ncbi.nlm.nih.gov/30482767/)
- Cited evidence (PMID 34352295) [PMID:34352295](https://pubmed.ncbi.nlm.nih.gov/34352295/)
- Cited evidence (PMID 33007077) [PMID:33007077](https://pubmed.ncbi.nlm.nih.gov/33007077/)
- Cited evidence (PMID 23808982) [PMID:23808982](https://pubmed.ncbi.nlm.nih.gov/23808982/)
- Cited evidence (PMID 22449293) [PMID:22449293](https://pubmed.ncbi.nlm.nih.gov/22449293/)

Last reconciled with current guidelines: 2026-05-15.
References