NEW EVIDENCE demonstrating an association between pregnancy complications and a patient history of migraines has recently been uncovered in a large prospective study. Migraine occurs in approximately 12% of the population of the USA each year, affecting a larger proportion of women (18% compared with 6% of men). Previous case–control and retrospective studies have suggested that migraine and adverse pregnancy outcomes are associated; however, until now, large prospective studies have been lacking.
Researchers evaluated 30,555 pregnancies among women in the longitudinal Nurses’ Health Study II from 1989 to 2009. In their evaluation, researchers assessed preterm delivery, gestational diabetes, gestational high blood pressure, pre-eclampsia, and low birth weight (defined as under 5.5 lb). Log-binomial regression was applied to account for multiple pregnancies per women.
In prospective models adjusted for age, adiposity, and behavioural and health factors, when compared to women who didn’t have pre-pregnancy migraine, women with pre-pregnancy migraine were found to have higher relative risks of preterm delivery (1.17; 95% confidence interval [CI]: 1.05–1.30), gestational hypertension (1.28; 95% CI: 1.11–1.48), and pre-eclampsia (1.40; 95% CI: 1.19–1.65). Furthermore, evidence showed that migraine with aura, the migraine phenotype most strongly associated with vascular risk, increased relative risk of pre-eclampsia further (1.51; 95% CI: 1.22–1.88) relative to patients with migraine without aura (1.29; 95% CI: 1.04–1.61).
Subsequent analysis found no association between pre-pregnancy migraine and low birth weight or gestational diabetes. The authors conceded that further research was needed as the study did not explore the impact of migraine frequency, or migraine features other than aura, on the risk of pregnancy complications.