Conference Coverage

Migraine linked to preeclampsia and other pregnancy complications



Pregnant women with a history of migraine are at elevated risk for gestational hypertension and preeclampsia, and of delivering their baby preterm, new research suggests. In a large prospective study, researchers also found a link between migraine with aura and increased preeclampsia risk.

Overall, the findings suggest women with a history of migraine may benefit from enhanced monitoring during pregnancy, said coinvestigator Alexandra Purdue-Smithe, PhD, associate epidemiologist at Brigham and Women’s Hospital and instructor of medicine at Harvard Medical School, Boston. “Our results suggest that migraine history may be an important consideration in obstetric risk assessment,” Dr. Purdue-Smithe added.

The findings will be presented at the 2022 annual meeting of the American Academy of Neurology.

Common neurovascular disorder

Migraine is a common neurovascular disorder, affecting about 15% of adults. The condition carries “a pretty remarkable sex bias” as it affects up to three times more women than men, and about a quarter of women in the reproductive age bracket of 18-44 years, Dr. Purdue-Smithe noted.

Despite this, relatively little is known about migraine and pregnancy risks, she said.

What is known is that women with migraine have a higher burden of cardiovascular risk factors such as obesity and chronic hypertension, and these factors can also increase risk for pregnancy complications, she added.

In the study, researchers analyzed data on 30,555 pregnancies in about 19,000 women without a history of cardiovascular disease, type 2 diabetes, or cancer during a 20-year period ending in 2009.

The data came from the Nurses’ Health Study II, a large prospective cohort study established in 1989 when it enrolled women aged 25-42 years. Participants in the ongoing study complete questionnaires every 2 years, reporting information on various health conditions as well as pregnancy and reproductive events.

The investigators estimated associations of physician-diagnosed prepregnancy migraine with preterm delivery, gestational diabetes, gestational hypertension, preeclampsia, and low birth weight (<2,500 grams [5.5 lb]).

About 11% of the women in the study had migraine diagnosed by a physician before pregnancy.

Researchers adjusted for age at pregnancy, race/ethnicity, age at menarche, and prepregnancy chronic hypertension, body mass index, physical activity, smoking status, alcohol intake, history of infertility, parity, oral contraceptive use, and analgesic use.

‘A bit surprising’

Results showed that compared with women without a history of migraine, those with such a history had higher risk for preterm delivery (relative risk [RR], 1.17; 95% confidence interval [CI], 1.05-1.30), gestational hypertension (RR, 1.28; 95% CI, 1.11-1.48), and preeclampsia (RR, 1.40; 95% CI, 1.19-1.65).

Prepregnancy migraine was not associated with low birth weight (RR, 0.99; 95% CI, 0.85-1.16) or gestational diabetes (RR, 1.05; 95% CI, .91-1.22).

It was a “bit surprising” that women with migraine had a higher risk for preterm delivery but their babies were not necessarily underweight – although some prior literature had similar findings, said Dr. Purdue-Smithe.

She noted that in her study the association was limited to moderate preterm delivery (gestational age, 32-37 weeks) and not with very preterm births (before 32 weeks).

Researchers also assessed adverse pregnancy outcomes by aura phenotype. “Women with migraine with aura have a higher risk of cardiovascular disease later in life, so we hypothesized that aura might be more strongly associated with adverse pregnancy outcomes with underlying vascular pathology,” Dr. Purdue-Smithe said.

Women with and without aura had elevated risks for preterm delivery and gestational hypertension. Those with aura had a slightly higher risk for preeclampsia (RR, 1.51; 95% CI, 1.22-1.88) than those without aura (RR, 1.29; 95% CI, 1.04-1.61).

As the association between migraine and adverse pregnancy outcomes persisted after adjustment for established cardiovascular and obstetric risk factors, “this suggests there may be subclinical factors that are contributing to elevated risks of these outcomes in women with migraine,” said Dr. Purdue-Smithe.

Such factors could include platelet activation, chronic inflammation, and endothelial dysfunction, she added.

While findings of some previous case-control and retrospective studies suggested a possible link between migraine and adverse pregnancy outcomes, until now few large prospective studies have examined the association.

“Strengths of our study include its prospective design, very large sample size, and more complete adjustment for potential prepregnancy confounders,” Dr. Purdue-Smithe said.


Next Article: