Which anticoagulant is considered a teratogen and should not be used during organogenesis in pregnant women?

The anticoagulant that is recognized as a teratogen and is contraindicated during organogenesis in pregnant women is warfarin. This is because warfarin crosses the placenta and has been associated with a range of fetal complications when exposed during the critical periods of organ development. Specifically, the use of warfarin during pregnancy can lead to embryopathy, characterized by various defects such as nasal hypoplasia, skeletal abnormalities, and central nervous system issues, often referred to as "warfarin embryopathy."

In contrast, low-dose aspirin and low-molecular-weight heparin are generally considered safer options during pregnancy. Low-dose aspirin is sometimes used to reduce the risk of complications like preeclampsia, while low-molecular-weight heparin does not cross the placenta and is preferred for anticoagulation needs during pregnancy due to its safety profile. Aspirin, when used in appropriate low doses, is also not classified as a teratogen in the context of limited use during pregnancy.

Therefore, the recognition of warfarin's potential teratogenic effects underscores its classification as a contraindicated medication during a critical phase of pregnancy, making it essential for healthcare providers to avoid its use in women who are pregnant or planning to become