Combined Hormonal Contraceptive not tied to significant stroke risk in Migraine with Aura

New research revealed that combined hormonal contraceptives (CHC) can be used by migraine patients as the overall stroke risk has reduced. The risk was lower in patients with migraine with aura than those without aura. The study was published in the journal Headache. 

Women of reproductive age, despite migraines, need an effective form of contraception. Migraine is a common headache disorder affecting women more than men. Some of the guidelines discourage the use of combined hormonal contraceptives in women due to the risk of stroke. This leads to non-adherence and non-alignment to contraceptive methods. As there were limited data and uncertainty on the factors affecting estrogen with a history of migraine and the impact of ischemic stroke risks associated with combined hormonal contraceptive (CHC) use researchers conducted a case-control analysis to study the CHC use in those with migraine with aura in a large tertiary care center. 

The analysis included women aged 18–55 who used a CHC between January 1, 2010, and December 31, 2019. Patients with stroke diagnoses were identified using ICD codes and confirmed via chart and imaging review. Other details like the personal and family medical history, stroke evaluation, ethinyl estradiol dosing (EE; ≥30 vs. <30 μg), and demographics were collected. About 635 control cohorts could be identified from a random sample of 20,000 CHC users without stroke and matched based on patient characteristics, medical and family histories, and stroke risk factors to assess the association between migraine diagnosis, migraine subtype, estrogen dose, and stroke.  

Key findings: 

• Of the 2,03,853 CHC users, 127 had confirmed stroke (0.06%; CI 0.05%, 0.07%).
• There was a higher number of patients in the case-cohort with migraine diagnosis (34/127, 26.8%) than controls (109/635, 17.2%; p = 0.011) in unadjusted analyses. 
• Stroke risk increased with ≥30-μg EE doses compared to those using a <30-μg dose.
• The odds of stroke increased with a personal history of migraine when compared to no migraine (OR, 2.00; CI 1.27, 3.17; p = 0.003).
• Compared to no migraine, stroke risk was not significantly increased in those with migraine with aura, but migraine without aura increased the risk (OR, 2.35; CI 1.32, 4.2; p = 0.004). 

Thus, the study showed that the increased risk of stroke in migraine patients was limited to those without aura. The researchers also suggested counseling, informed and shared decision-making in the use of CHCs in migraine. 

Further reading: Batur P, Yao M, Bucklan J, et al. Use of combined hormonal contraception and stroke: A case-control study of the impact of migraine type and estrogen dose on ischemic stroke risk [published online ahead of print, 2023 Feb 8]. Headache. 2023;10.1111/head.14473. doi:10.1111/head.14473