Patient handout

DVT during pregnancy / postpartum

PRODUCTION

1. Your condition

This handout is for dvt during pregnancy / postpartum. Your care team identified this based on: 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).

Other reasons your team may use this plan: 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); pregnant patient with dvt plus dyspnea, pleuritic chest pain, syncope, or hypoxemia → image for concurrent pe (ct-pa radiation acceptable; <0.1 mgy fetal dose).

2. Your medications

Take these medications exactly as prescribed. Do not stop or change a dose without talking to your provider.

Medication	Starting dose	How	When	What it does
enoxaparin	1 mg/kg SC q12h (weight-based; titrate q4 wk as pregnancy weight increases)	SC	q12h throughout pregnancy + ≥6 wk postpartum	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
dalteparin	200 IU/kg SC daily OR 100 IU/kg SC BID	SC	daily or BID	ASH 2018; alternative LMWH; same safety profile in pregnancy
heparin	80 U/kg bolus + 18 U/kg/h infusion targeting aPTT 1.5-2.5×	IV	continuous	ASH 2018; UFH preferred when reversibility needed (rapid onset/offset, protamine reversible); transitions in late 3rd trimester common
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	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)
apixaban	AVOID in pregnancy AND breastfeeding	PO	avoided	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

Plan: Pregnancy DVT — LMWH antepartum + 6-wk postpartum (ASH 2018 + RCOG 37a)

3. When to call your provider

Contact your care team if any of the following happen:

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

4. When to seek emergency care

Call 911 or go to the nearest emergency room right away if you have:

Active vaginal bleeding, postpartum hemorrhage, or hematoma in pregnant or peripartum patient on therapeutic LMWH or UFH(life-threatening)
New DVT or PE during the 6-wk postpartum window despite therapeutic LMWH — heparin failure or escalation indication
Pregnancy discovered while on DOAC OR DOAC inadvertently prescribed antepartum — pregnancy exposure with limited safety data
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)(life-threatening)

5. Follow-up

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

6. Sources

Guideline: ASH 2018 VTE in Pregnancy + ACCP/CHEST 2018 / 2021 + RCOG Green-top 37a + ACOG Practice Bulletin 196