Blood thinners during pregnancy, labor and delivery

Studies show that some blood thinners do not cross the placenta. These include heparin and low molecular weight heparin, such as enoxaparin (Lovenox). They can be used during pregnancy when monitored closely. Some pregnant people with AFib get low molecular weight heparin shots to prevent blood clots.

Even when taking a blood thinner, blood clots may happen during pregnancy. Watch for symptoms of blood clots such as:

• Chest pain.
• Shortness of breath.
• Leg swelling.

Get help right away if you have symptoms of stroke, including:

• Changes in vision.
• Trouble speaking.
• Numbness in the face, arms or legs.

Get medical help right away if you notice any other unusual symptoms.

Heparin and other blood thinners increase the risk of major bleeding. This includes bleeding where the placenta attaches to the uterus. If you have any bleeding, tell your healthcare team. Blood thinners are often stopped during labor and delivery unless you're at very high risk of blood clots.