Women are 2-3 times more likely than men to experience migraine in their lifetime, and the prevalence of migraine is highest (23.5%) among women aged 18-44 years. Migraine and adverse pregnancy outcomes (APOs) share common pathophysiology, and both are associated with cardiovascular disease risk. Whether pre-pregnancy migraine and aura phenotype might serve as clinically useful markers of obstetric risk is unclear, as large prospective studies are lacking.
Objective
To examine longitudinal associations of pre-pregnancy migraine and aura phenotype with risks of APOs.
Design
Prospective cohort study.
Setting
Nurses’ Health Study II (1989-2009).
Participants 30,555 incident pregnancies among 19,694 women without a history of cardiovascular disease, diabetes, or cancer.
Exposures
Self-reported physician-diagnosed migraine prior to pregnancy and aura phenotype.
Outcome measures
Relative risks (RR) and 95% confidence intervals (CI) for gestational diabetes mellitus (GDM), preeclampsia, gestational hypertension, preterm delivery, and low birthweight.
Results
After adjusting for health and behavioral factors, pre-pregnancy migraine (11%) was associated with higher risks of preterm delivery (RR=1.17; 95% 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) compared to women without pre-pregnancy migraine. Migraine was not associated with low birthweight (RR=0.99; 95% CI=0.85-1.16) or GDM (RR=1.05; 95% CI=0.91-1.22). Risk of preeclampsia was slightly higher among women with migraine with aura (RR versus no migraine=1.51; 95% CI=1.22-1.88) than migraine without aura (RR versus no migraine=1.29; 95% CI=1.04-1.61). Regular pre-pregnancy aspirin use modified the association of pre-pregnancy migraine with preterm delivery (<2x/wk RR=1.24; 95% CI=1.11-1.38; ≥2x/wk RR=0.55; 95% CI=0.35-0.86) and preeclampsia (<2x/wk RR=1.48; 95% CI=1.25-1.75; ≥2x/wk RR=1.10; 95% CI=0.62-1.96).
Conclusions
Migraine history, and to a lesser extent aura phenotype, appear to be important considerations in obstetric risk assessment and management. Future research should elucidate the mechanisms underlying these associations and further explore aspirin prophylaxis to reduce risks of APOs in women with migraine.