Young pregnant women more at risk of stroke: Study

Pregnancy in young women may increase the risk of stroke as compared to their older counterparts of childbearing age, a study has found.

The findings showed that stroke risk was more than doubled in women aged 12 to 24 years and increased significantly by 60 per cent in women 25 to 34 years during pregnancy or post partum period up to six weeks after delivery. However, there was no difference in stroke risk in women 35 years or older. 

"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 lead author Eliza C. Miller from Columbia University Medical Centre (CUMC) in New York, US. 

"But in women under 35, pregnancy significantly increased the risk of stroke. In fact, one in five strokes in women from that age group were related to pregnancy," Miller added.

Previous studies suggested that the risk of pregnancy-associated stroke is higher in older women than in younger women.

"The incidence of pregnancy-associated strokes is rising, and that could be explained by the fact that more women are delaying childbearing until they are older, when the overall risk of stroke is higher," noted Joshua Z. Willey, Assistant Professor at CUMC and neurologist at New York-Presbyterian Hospital in the US.

In the study, the team examined 19,146 women, aged 12 to 55 years. Of these, 797 (4.2 per cent) were pregnant or had just given birth.

They found that the overall incidence of stroke during or soon after pregnancy increased 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, pregnant and postpartum women in the youngest group (age 12 to 24) had more than double the risk of stroke than non-pregnant women in the same age group (14 per 100,000 in pregnant women vs 6.4 in non-pregnant women).

"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," Miller said. 

The results appear in the journal JAMA Neurology.