Results from a large preliminary study, that will be presented at the American Academy of Neurology’s 74th Annual Meeting, suggest that women with migraine have significantly increased risk for preterm delivery, pre-eclampsia and high blood pressure during pregnancy compared with women without migraine.
Migraine, presenting as severe headaches with or without a visual aura, is a common condition occurring in 10–20% of the population. It is up to three-times more common in reproductive age women than in men of a similar age.
“Roughly 20% of women of childbearing age experience migraine, but the impact of migraine on pregnancy outcomes has not been well understood,” said study author Alexandra Purdue-Smithe, of Brigham and Women’s Hospital in Boston, in a press statement. “Our large prospective study found links between migraine and pregnancy complications that could help inform doctors and women with migraine of potential risks they should be aware of during pregnancy.”
To investigate whether women with chronic migraines are at increased risk for pregnancy complications, the researchers carried out a study including 30,555 pregnancies that occurred between 1989 and 2009. The pregnant women (aprx. 19,000) formed part of the ongoing Nurses’ Health study cohort. This long-term study was started in the 1970’s and is still ongoing. Including almost 300,000 participants, it is one of the largest studies researching risks for chronic diseases in women.
Overall, the research team assessed the risk of five possible complications: preterm delivery (at less than 37 weeks), gestational diabetes, gestational high blood pressure or hypertension, preeclampsia, and low birthweight (less than 5.5 lbs, or 2.5 kg).
There was no difference in rates of gestational diabetes or low birth weight between pregnant women with migraine (3,881 women) and those without. However, rates of preterm delivery, gestational hypertension and pre-eclampsia were higher in pregnant women with migraine with relative risk increases of 17%, 28% and 40%, respectively, compared with women without migraine.
Notably, when the analysis split those who experienced migraine into those who also experienced aura and those who did not, the relative risk increases for pre-eclampsia compared with women without migraine were higher in the aura group at 51% versus 29%.
The authors note that data on whether or not the women in the study experienced an aura with migraines was only collected later, after pregnancies ended, so may be impacted by how well the women remembered their symptoms. Other data such as migraine frequency was also not collected.
“While the risks of these complications are still quite low overall, women with a history of migraine should be aware of and consult with their doctor on potential pregnancy risks,” said Purdue-Smithe.
“More research is needed to determine exactly why migraine may be associated with higher risks of complications. In the meantime, women with migraine may benefit from closer monitoring during pregnancy so that complications like preeclampsia can be identified and managed as soon as possible.”