Stillbirth and miscarriage are ‘specific risk factors for stroke’

Posted: 04/07/2022

The British Medical Journal has recently published research which confirms that there is a link between pregnancy loss and a woman’s risk of suffering a stroke. The study, which considered outcomes for more than 600,000 women across seven countries, confirmed that the more miscarriages or stillbirths a woman experiences, the higher her risk of having a stroke.

The results of the study showed that women with infertility were at an increased risk of non-fatal stroke, and women who had experienced a miscarriage or stillbirth were at an increased risk of both non-fatal and fatal stroke. In an article for The Conversation, the authors of the research highlighted the key statistics from the report, including:

• When compared with women who had not had a miscarriage, women reporting a miscarriage had an 11% higher risk of a non-fatal stroke, and 17% higher risk of a fatal stroke.
• The risk of stroke increased with each miscarriage – compared with women who had never miscarried, women who had three or more miscarriages had a 35% higher risk for non-fatal stroke, and an 82% higher risk of fatal strokes.
• Women who had experienced a stillbirth had a 31% higher risk of non-fatal strokes, and a 7% higher risk of fatal strokes.
• Women who had experienced two or more stillbirths had a 26% higher risk of fatal strokes.

Interestingly, the research identified an increased risk for different subtypes of stroke following different types of pregnancy loss. There are two different categories of stroke: ischaemic strokes, which are those caused by a clot blocking the blood supply to the brain, and haemorrhagic strokes, which are caused by bleeding from a burst blood vessel.

The study confirmed that ‘the increased risk of stroke associated with infertility or recurrent stillbirths was mainly driven by a single stroke subtype (non-fatal ischaemic stroke and fatal haemorrhagic stroke), while the increased risk of stroke associated with recurrent miscarriages was driven by both subtypes’.

While the reason behind the increased risk of stroke needs further investigation, the researchers have suggested possible explanations, including that ‘problems with endothelial cells (which control vascular relaxation and contraction as well as release blood clotting enzymes) might lead to pregnancy loss through problems with the placenta. These problems also relate to how blood vessels dilate and get inflamed or blocked during a stroke.’

The conclusion to this research emphasises the fact that these findings should be used by doctors to improve outcomes for women: ‘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.’

In commenting on the clinical implications, the researchers suggest that women who have experienced multiple miscarriages and stillbirths should receive earlier monitoring for stroke risk factors, including raised blood pressure and blood sugar levels. They should also be provided with information about adopting a healthy lifestyle to reduce their own risk. This would include stopping smoking, and eating well and exercising to maintain a healthy weight.   

Sarah Hibberd, a clinical negligence lawyer specialising in both maternal injury claims and stroke cases, has commented: “While this is difficult news for anyone who has already gone through the significant trauma of infertility or losing a child, this research will help to identify women who are more at risk of stroke, so that they can be properly monitored and preventative measures can be taken to reduce their risk.

“Doctors should be aware of their patient’s reproductive history, and how that impacts on their stroke risk, so it can be taken into account when advising on treatment options or lifestyle changes. Doctors should also be alert to identifying the signs and symptoms of TIAs (mini strokes) and strokes to ensure that anyone having a stroke receives prompt and appropriate treatment to reduce the extent of their injury.”  

If you have any concerns about medical treatment you have received before or after a stroke, or during your pregnancy, please do not hesitate to contact our specialist clinical negligence team for a free no obligation discussion.

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