Study examines if migraine is tied to complications in pregnancy

Does migraine have any implication on pregnant women? Does a mother's body issue have an effect on the unborn baby? According to a preliminary study, women with migraine may have a higher risk of pregnancy complications like preterm delivery, gestational high blood pressure and preeclampsia.

The preliminary study, released by the 'American Academy of Neurology', will be presented at its 74th Annual Meeting being held in person in Seattle, April 2 to 7, 2022 and virtually, April 24 to 26, 2022.

Researchers also found that women with migraine with aura may have a somewhat higher risk of preeclampsia than women with migraine without aura. Auras are sensations that come before the headache, often visual disturbances such as flashing lights. Preeclampsia involves high blood pressure with additional symptoms, such as protein in the urine, during pregnancy, which can threaten the life of the mother and baby.

"Roughly 20 per cent 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, PhD, of Brigham and Women's Hospital in Boston. "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."

For the study, researchers looked at more than 30,000 pregnancies in roughly 19,000 women over a 20-year period. Of those pregnancies, 11 per cent of the women reported that they were diagnosed by a doctor with migraine before pregnancy.

Researchers examined women's complications during pregnancy such as preterm delivery, defined as a baby born before 37 weeks gestation, gestational diabetes, gestational high blood pressure, preeclampsia, and low birth weight.

After adjusting for age, obesity, and other behavioural and health factors that could affect the risk of complications, researchers found that when compared to women without migraine, women with migraine had a 17 per cent higher risk of preterm delivery, a 28 per cent higher risk of gestational high blood pressure, and a 40 per cent higher risk of preeclampsia. Of the 3,881 pregnancies among women with migraine, 10 per cent were delivered preterm, compared to 8 per cent of the pregnancies among women without migraine. For gestational high blood pressure, 7 per cent of pregnancies among women with migraine developed this condition compared to 5 per cent among pregnancies in women without migraine. For preeclampsia, 6 per cent of pregnancies among women with migraine experienced it, compared to 3 per cent of pregnancies among women who did not have migraine.

In addition, when looking at migraine with and without aura, women who had migraine with aura were 51 per cent more likely to develop preeclampsia during pregnancy than women without migraine, while those who had migraine without aura were 29 per cent more likely.

Researchers found that migraine was not associated with gestational diabetes or low birth weight.

"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."

A limitation of the study was that although migraine history was reported prior to pregnancy, information on migraine aura was not collected until later in the study after many of the pregnancies ended. So the findings for migraine aura may have been influenced by participants' ability to accurately remember their experiences. Another limitation is that information on migraine attack frequency and other migraine features were not available. Additional studies will be needed to address these limitations and better inform how pregnant women with a history of migraine should be screened and monitored for potential pregnancy complications.

The study was supported by the National Institutes of Health.