Comparative Effects of Estrogen Use Status and Route of Administration on Migraine Risk in Postmenopausal Women: A Network Meta-Analysis [ID 3596]

INTRODUCTION: Migraine is a common complaint among postmenopausal women receiving hormone replacement therapy (HRT). Concerns exist that estrogen use and administration routes may influence migraine risk. This network meta-analysis evaluates the association of estrogen use (current, previous, and no use) and administration routes (oral, transdermal, and vaginal) with migraine incidence in postmenopausal women. METHODS: A systematic search of PubMed, Embase, Web of Science, and Cochrane Library identified studies comparing migraine incidence by estrogen use and route of administration. A network meta-analysis was performed using relative risk (RR) estimates and 95% credible intervals (CrI). RESULTS: Two studies, including 22,614 patients, were analyzed. Current HRT use was associated with a significantly higher migraine risk compared with no use (RR 1.49; 95% Crl, 1.12–1.99). No significant associations were observed for current versus previous use (RR 1.29; 95% Crl, 0.87–1.95) or previous versus no use (RR 1.16; 95% Crl, 0.78–1.72). Regarding administration routes, no significant differences were found between oral and vaginal (RR 1.54; 95% Crl, 0.80–2.89), oral and transdermal (RR 0.82; 95% Crl, 0.51–1.37), or vaginal and transdermal (RR 0.53; 95% Crl, 0.28–1.07). CONCLUSIONS/IMPLICATIONS: Although current estrogen use was associated with an increased risk of migraine, no differences were detected across administration routes or when comparing previous with no use. These findings suggest that HRT decisions should be individualized based on patient preference, tolerability, and overall clinical context rather than migraine risk alone.