Migraine ups stroke risk in pregnancy

Women who suffer with migraine are at an increased risk of having a stroke during pregnancy, the results of a new study indicate.

According to the findings, these women are also an increased risk of suffering other vascular conditions during pregnancy, such as heart disease, high blood pressure and blood clots.

Migraine is characterised by a severe, one-sided headache that can last up to three days. It can be accompanied by symptoms such as nausea, vomiting and sensitivity to light and/or noise. Around one-quarter of women of childbearing age are affected. In the 35-39 age group, this rises to one-third.

However little is known about the prevalence of migraine during pregnancy. As a result, US researchers set out to test the association between migraine and vascular diseases during pregnancy.

Using a national database of over 18 million hospital discharge records, they identified 33,956 pregnancy-related discharges with a diagnosis of migraine covering the period 2000 to 2003.

The study found that migraines during pregnancy were linked to a 15-fold increased risk of stroke. Migraine also tripled the risk of blood clots in the veins and doubled the risk of heart disease.

Even when pre-eclampsia – a pregnancy condition which is the most influential factor in relation to migraine – was removed from the analysis, there was little change in the results. This suggests that these are independent associations.

However the researchers emphasised that overall, stroke in pregnancy is very rare – around four cases per 100,000 births. They also pointed out that these results will not apply to every woman with migraine during pregnancy.

Nevertheless, for pregnant women admitted to hospital with active migraines, doctors should recognise and help to reduce cardiovascular risk factors and should treat complications of pregnancy such as pre-eclampsia, they said.

The team from Wake Forest University Health Sciences in North Carolina suggested that the most logical explanation for these findings lies in the interaction between migraines and the normal physiological changes during pregnancy, such as increased blood volume and heart rate, which put extra stress on the vascular system.

“But regardless of the mechanism, active migraine during pregnancy could be viewed as a potential marker of vascular diseases, especially stroke. Although cause and effect still need to be established, the results of this study lay the groundwork for future studies related to migraine and pregnancy,” they added

Details of these findings are published in the British Medical Journal.

For more information on heart disease, see…http://www.heart.ie

[Posted: Wed 11/03/2009]