Which statement about low molecular weight heparin (LMWH) use in pregnancy is true?

Which statement about low molecular weight heparin (LMWH) use in pregnancy is true?

• A. Has more side effects and a shorter half-life
• B. Has fewer side effects and a longer half-life
• C. Requires no monitoring
• D. Is reversed rapidly with vitamin K

Answer: (B)

Low molecular weight heparin (LMWH) is favored in pregnancy because it provides effective anticoagulation with fewer adverse effects and a longer half-life than unfractionated heparin. The longer half-life means dosing can be simpler and less frequent, which is more convenient for both the patient and care team. In addition, LMWH’s ability to do most of its work without requiring routine coagulation monitoring makes it safer and easier to manage during pregnancy. It also does not cross the placenta in meaningful amounts, offering fetal safety. Monitoring with anti-Xa levels is not routinely required, though it may be used in certain situations (such as obesity, renal impairment, or extreme body weight). Reversal is not rapid with vitamin K—vitamin K reverses warfarin, not LMWH; protamine sulfate can partially reverse LMWH if needed. That combination of fewer side effects and a longer half-life is what makes LMWH the best choice among the options.

Low molecular weight heparin (LMWH) is favored in pregnancy because it provides effective anticoagulation with fewer adverse effects and a longer half-life than unfractionated heparin. The longer half-life means dosing can be simpler and less frequent, which is more convenient for both the patient and care team. In addition, LMWH’s ability to do most of its work without requiring routine coagulation monitoring makes it safer and easier to manage during pregnancy. It also does not cross the placenta in meaningful amounts, offering fetal safety. Monitoring with anti-Xa levels is not routinely required, though it may be used in certain situations (such as obesity, renal impairment, or extreme body weight). Reversal is not rapid with vitamin K—vitamin K reverses warfarin, not LMWH; protamine sulfate can partially reverse LMWH if needed.

That combination of fewer side effects and a longer half-life is what makes LMWH the best choice among the options.