Table 28.

Anticoagulation Strategies During Pregnancy

Antenatal Options
	Method 1	Method 2	Method 3	Alternative Method 4
First trimester	Warfarin ≤5 mg	LMWH	UFH	LMWH
Second trimester	Warfarin	Warfarin	Warfarin	LMWH
Third trimester	Warfarin	Warfarin	Warfarin	LMWH

Delivery Planning
	Method 1	Method 2
1 wk before	Discontinue warfarin → continuous IV U FH	Dose-adjusted LMWH
36 h before	Continuous IV UFH	Switch to continuous IV UFH
4–6 h before	Stop IV heparin	Stop IV heparin

Adapted with permission from Otto et al.¹⁵ Copyright 2021 American Heart Association, Inc., and American College of Cardiology Foundation.

IV indicates intravenous; LMWH, low-molecular-weight heparin; and UFH, unfractionated heparin.