Idiopathic Intracranial Hypertension Prevalence and Hormonal Contraception: A Meta-Analysis.

Abstract

Women's health advice in people living with idiopathic intracranial hypertension (IIH) is inconsistent, primarily due to an enduring concern that hormonal contraception (HC), including oral contraceptive pills (OCPs) and hormonal intrauterine devices (IUDs), might be associated with a higher prevalence of IIH. This systematic review and meta-analysis examines whether a meaningful association exists between HC use and IIH prevalence. Systematic searches of Ovid MEDLINE, Embase, and the Cochrane Library were conducted from their inception to May 14, 2025. Gray literature and citation lists were also reviewed. Observational studies comparing HC use among women with IIH to controls without IIH were included. Noncomparative studies and pharmacovigilance analyses were excluded. Two independent reviewers conducted data extraction, assessed the quality of studies using the Newcastle-Ottawa Scale, and appraised the certainty of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation framework. A random-effects meta-analysis using the Mantel-Haenszel method in Review Manager 5.4 was conducted to evaluate the association between HC use and IIH prevalence, the primary outcome of interest, with leave-one-out sensitivity analyses and subgroup analyses stratified by HC modality. A total of 13 studies (n_IIH = 5,351 and n_control = 669,260; mean age = 33.3 years; 100% female) were included. HC use was not significantly associated with IIH prevalence (odds ratio [OR] 0.93, 95% CI 0.69-1.24, <i>p</i> = 0.60, <i>I</i>² = 82%; n = 12 studies). Subgroup analyses revealed no significant associations for OCPs (OR 0.91, 95% CI 0.72-1.16, <i>p</i> = 0.45, <i>I</i>² = 25%; n = 6 studies), IUDs (OR 1.45, 95% CI 0.61-3.44, <i>p</i> = 0.39, <i>I</i>² = 92%; n = 5 studies), or medroxyprogesterone acetate injections (OR 1.21, 95% CI 0.84-1.74, <i>p</i> = 0.30, <i>I</i>² = 2%; n = 2 studies). Findings were largely robust in sensitivity analyses. Quality assessments ranged from poor to good, with the certainty of evidence rated as very low to low. The meta-analysis found no significant association between HC use and IIH prevalence, with consistent results across various HC modalities. This evidence provides confidence to reassure patients with IIH and clinicians that the directed use of HC should be continued as appropriate. The limited quality of available evidence and considerable heterogeneity highlights the necessity for large-scale, well-designed studies, particularly in diverse patient populations, to validate these findings.