HEPARIN IS CONSIDERED THE ANTICOAGULANT OF CHOICE MOST OF THE TIME DURING PREGNANCY BECAUSE

• A. Warfarin is teratogenic in the first trimester and heparin does not cross the placenta ✓
• B. It is metabolized by the kidneys
• C. It is metabolized by the liver
• D. It does not induce preterm labor
• E. This is not true. Warfarin is the anticoagulant of choice during pregnancy

Heparin is considered the anticoagulant of choice during pregnancy for several reasons, one of which is that warfarin, a commonly used anticoagulant, is known to be teratogenic in the first trimester of pregnancy. Teratogenicity refers to the ability of a substance to cause developmental abnormalities in a fetus when exposed to it during pregnancy. Warfarin has been associated with an increased risk of birth defects when used in the first trimester, particularly affecting the development of the baby’s bones and central nervous system.

On the other hand, heparin is preferred because it does not cross the placenta. The placenta acts as a barrier between the maternal and fetal circulations, allowing essential nutrients and oxygen to pass from the mother to the fetus while preventing harmful substances from reaching the developing baby. Since heparin does not cross this barrier, it can effectively prevent blood clot formation in the mother without posing a direct risk to the fetus.

In summary, heparin’s inability to cross the placenta reduces its potential impact on fetal development compared to warfarin, making it a safer choice for anticoagulation during pregnancy.