Infertility, miscarriage and stillbirth have been linked to an increased risk of stroke in a new study.
Experts examined global data and found that women who had had three miscarriages or more appeared to have a 35% increased risk of non-fatal stroke, or one resulting in death.
One miscarriage was linked to a 7% increased risk of non-fatal stroke, while two was linked to a 12% increased risk.
For fatal stroke, women with one miscarriage had an 8% increased risk, two was linked to a 26% increased risk and three was linked to an 82% increased risk.
The study also found that women who had suffered stillbirth were at 31% higher risk of a non-fatal stroke and 7% increased risk of fatal stroke.
Meanwhile, recurrent stillbirth was linked to a 26% higher risk of fatal stroke.
Infertility was also linked to a 14% higher risk of non-fatal stroke compared to women who were fertile.
Researchers suggested possible reasons for the findings, including that the link between infertility and increased stroke risk may be due to conditions such as polycystic ovary syndrome (PCOS) and premature ovarian insufficiency (POI).
A narrowing of the heart’s blood vessels may also explain the increased risk of stroke for women with a history of recurrent stillbirth or miscarriage.
However, the team also said unhealthy lifestyles contribute to stroke risk, as they called for more research into the area.
Writing in the British Medical Journal (BMJ), the experts, including from the University of Queensland in Australia and University College London, concluded: “A history of recurrent miscarriages and death or loss of a baby before or during birth could be considered a female-specific risk factor for stroke, with differences in risk according to stroke subtypes.
“These findings could contribute to improved monitoring and stroke prevention for women with such a history.”
For the study, the team looked at eight lots of research carried out in Australia, China, Japan, the Netherlands, Sweden, the United Kingdom and the US.
Overall, more than 600,000 women aged 32 to 73 at the start of the study were included, of which 9,265 experienced a first non-fatal stroke (2.8%), typically aged 62, and 4,003 (0.7%) experienced a fatal stroke, typically aged 71.
Strokes were identified through self-reported questionnaires, hospital data or national patient registers.
Fatal strokes were recorded through death registries.
Factors that may influence the results, such as body mass index and whether women smoked, were taken into account. Women with non-fatal stroke before the age of 40 were excluded.
Globally, stroke is one of the leading causes of death and disability in women.
In 2019, figures suggest around three million women died from stroke and millions more live with ongoing disability.