Table 2.

Hazard ratio of gestational headache in each of the four outcomes considering interaction with history of headache disorder

	Adjusted hazard ratio (95% confidence interval)a
	Any stroke	Ischemic stroke	Hemorrhage stroke	ICH	SAH
Gestational headache	1.39 (1.11–1.75)	1.19 (0.84–1.69)	1.49 (1.10–2.02)	1.63 (1.17–2.28)	1.12 (0.57–2.20)
History of headache	1.61 (1.21–2.14)	1.83 (1.26–2.67)	1.53 (1.03–2.28)	1.99 (1.33–2.96)	1.35 (0.59–3.06)
Interaction term (G-HA x Hx-HA)	1.65 (0.97–2.83)	2.11 (1.04–4.32)	1.38 (0.64–2.98)	0.68 (0.26–1.75)	4.29 (1.15–16.03)

G-HA Gestational headache, Hx-HA History of headache disorder, ICH = intracerebral hemorrhage, SAH = subarachnoid hemorrhage. ^aEach outcome was additionally adjusted for age, hypertension, diabetes, functional disability, gestational hypertension, and gestational diabetes