It is not something new mothers typically think about, but when a woman gives birth, her risk of stroke increases considerably. Strokes are usually thought of as medical events that occur in older people, but when it comes to childbirth, young healthy women are also at risk.

A recent study, published in the New England Journal of Medicine, finds that a woman who has just given birth is at an increased risk of stroke for three months after delivery.

The risk of stroke in the new mothers was 10.8 times higher during the first six weeks after delivery.

The risk is greatest in the first six weeks following birth, but it does not return to normal pre-pregnancy levels until about 12 weeks. The investigators looked at the health records for over 1.6 million women admitted for labor and delivery between 2005 and 2010. About a thousand of these women developed a clot which presented as a stroke, heart attack, pulmonary embolism, or deep vein thrombosis in the year and a half following delivery.

Changes in New Moms

The risk of stroke in the new mothers was 10.8 times higher during the first six weeks after delivery; two times higher from seven to 12 weeks post-delivery.

New mothers are at such high risk for stroke because pregnancy creates physiological changes in their bodies. Women's blood clots more easily during pregnancy and childbirth — to prevent excessive bleeding during and after delivery.

Women who are pregnant may develop elevated blood pressure, which may lead to preeclampsia or eclampsia and elevated stroke risk.

For some women the greater risk of stroke during and after pregnancy is made worse by risk factors seen in the general population: high blood pressure, diabetes, valvular heart disease, clotting disorders, sickle cell disease, lupus, abuse of tobacco and other substances, and migraines.

Women who are pregnant may develop elevated blood pressure, which may lead to preeclampsia or eclampsia and elevated stroke risk.

Even though the study found an increased risk of stroke among new mothers, it is important to note that stroke is an uncommon complication of pregnancy and delivery. Fewer than one in 10,000 women develop a pregnancy-related blood clot six to 12 weeks after delivery.

Who Is Most at Risk; What to Look For

Still, the risk merits a high level of awareness because the clinical outcomes of stroke are often catastrophic, leading to permanent disability or death. For this reason the relative increase in risk for up to 12 weeks postpartum should inform women's use of certain medications, such as oral contraception or anticoagulants; and the increased risk of engaging in high-risk behaviors such as smoking.

It is also useful for families to be aware of women's increased risk of stroke since they might otherwise fail to recognize the signs and symptoms of a stroke because they are not expecting such an event in a young, healthy woman.

The signs of stroke for which immediate medical attention should be sought include the following:

  • Sudden numbness or weakness of the face, arm, or leg on one side of the body
  • Sudden confusion, difficulty talking or understanding
  • Sudden trouble seeing on one side
  • Sudden, severe difficulty walking, dizziness, loss of coordination or balance
  • Sudden, severe headache for no known reason

Deep Vein Thrombosis (DVT)
While deep vein thromboses (blood clots in the legs) often have no symptoms, they may present with:

  • Swelling in one or both legs
  • Pain or tenderness in one or both legs, which may occur only while standing or walking
  • Warmth in the skin of the affected leg
  • Red or discolored skin in the affected leg
  • Visible surface veins
  • Leg fatigue

Pulmonary Embolism
A pulmonary embolus (blood clot in the lungs) occurs when a piece of a clot in a leg vein breaks off and travels through the circulation to the lungs. It may cause sudden coughing that may produce blood, sharp chest pain, fast breathing, shortness of breath and lightheadedness.

Minimizing Your Risk

Regular prenatal care is the best way to make sure that the risk factors for stroke and other pregnancy-related complications are routinely screened for and addressed. Give your doctor honest and accurate information regarding your past and current health issues, and any lifestyle choices like smoking that may affect your risk of stroke.

Knowing that changes to your body during pregnancy and childbirth can make a blood clot more likely will hopefully encourage you to pay more attention to your diet and do what you can to control your blood pressure — such as exercising. It's also important to pay attention to the labels of any medications you use, noting if they particularly warn against use if pregnant.

After your baby is born, follow up with your OB/GYN and report any symptoms. Tell your doctor about any change in blood pressure. Seek medical attention immediately if any of the signs or symptoms of stroke, blood clots, or heart attack are present. Getting prompt medical attention can make a big difference when it comes to recovering from stroke.