Last Updated on October 25, 2016 at 10:25 AM
Health In Focus
  • Pregnancy is known to increase the risk of stroke.
  • Until now, research has indicated that risk of pregnancy associated stroke is higher in older women.
  • Study compares risk of stroke on two groups of women  who are either less than 35 years or over 35 years and who are either pregnant or not pregnant
  • Risk of pregnancy related stroke is higher in younger women less than 35 years than in older women.

Incidence of pregnancy related stroke is greater in younger women than in older women, suggests a recent study from Columbia University Medical Center and New York-Presbyterian.
Pregnancy Related Stroke Risk Higher in Women Less Than 35 Years Compared to Older Women

What Did the Study Aim to Establish

The research team from Columbia University Medical Center and New York-Presbyterian wished to compare the incidence of stroke in women in the pregnant state versus incidence in the not pregnant state, belonging to the same age group.

Earlier studies have indicated that risk of pregnancy-associated stroke is higher in older women than in younger women. The reason for this finding might be due to the fact that women nowadays delay childbearing until they are older, when the overall incidence of stroke is more, said one of the study authors.

"However, very few studies have compared the incidence of stroke in pregnant and non-pregnant women who are the same age", said Joshua Z. Willey, MD, assistant professor of neurology at CUMC, assistant attending neurologist on the stroke service at New York-Presbyterian/Columbia, and a senior author on the paper.

Details of the Study

In this study, the researchers collected information regarding every woman hospitalized due to  stroke in New York State between the years 2003 and 2012.  Among the 19,146 women, aged between 12 to 55 years, 797 (4.2 percent) were either pregnant or had just given birth.

The researchers reported the following results

  • The overall incidence of stroke during or soon after pregnancy (postpartum) rose with age (46.9 per 100,000 in women age 45 to 55 vs 14 per 100,000 in women age 12 to 24).
  • However, the risk of stroke in pregnant and postpartum women in the youngest group (age 12 to 24) was more than twice that of non-pregnant women in the same age group (14 per 100,000 in pregnant women vs 6.4 in non-pregnant women).
  • In women aged 25 to 34,  pregnancy increased the risk of stroke by 1.6 times. The risk of stroke was same in pregnant and non-pregnant women after 35 years of age. ).

"We have been warning older women that pregnancy may increase their risk of stroke, but this study shows that their stroke risk appears similar to women of the same age who are not pregnant," said Eliza C. Miller, MD, a vascular neurology fellow in the Department of  Neurology at CUMC and New York-Presbyterian and lead author of the study.  "But in women under 35, pregnancy significantly increased the risk of stroke. In fact, 1 in 5 strokes in women from that age group were related to pregnancy. We need more research to better understand the causes of pregnancy-associated stroke, so that we can identify young women at the highest risk and prevent these devastating events."

Possible Causes of Pregnancy Associated Stroke

Stroke refers to brain damage and dysfunction that occurs following a vascular cause namely arterial occlusion and hemorrhage. It is one of the most common reasons for long term morbidity.

Many studies have shown that pregnancy increases the risk of stroke, but data available varies greatly. Interestingly, some studies have found that the incidence of stroke increased immediately after delivery (postpartum period), than actually during the pregnancy.

Risk Factors for Stroke and Cerebral Venous Thrombosis in Pregnancy

The risk factors of pregnancy associated stroke are manifold, with some of them preexisting, and others occurring during pregnancy or delivery. They include
  • Hypertension
  • Preeclampsia and eclampsia
  • Diabetes
  • Valvular heart disease
  • Hypercoagulable states
  • Sickle cell disease
  • Lupus
  • Migraines
  • Tobacco or other substance abuse
Complications related to pregnancy, and delivery may also increase the risk of stroke, such as -

  • Excessive morning sickness (hyperemesis gravidarum)
  • Anemia
  • Thrombocytopenia
  • Postpartum bleeding
  • Fluid, electrolyte and acid-base disorders
  • Transfusion and Infection

Preventing Pregnancy Associated Stroke

Although data varies widely, many experts suggest that in pregnant women with identifiable risk factors for stroke such as hypertension, diabetes, age more than 35 years, obesity, hyperlipidemia, previous eclampsia, valvular heart disease and renal disease, the following lines of management may be considered, after weighing the risks against the benefits specific to each patient.

  • Low dose aspirin during pregnancy
  • Unfractionated heparin (UFH) or low molecular weight heparin (LMWH)

Although incidence of stroke is generally less in younger women, its incidence associated with pregnancy is on the rise, attributable to various factors. It is therefore important to identify risk factors during pregnancy if any, and initiate prompt management to prevent the occurrence of this devastating condition.

  1. Pregnancy and Stroke Risk in Women - (
Source: Medindia

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