Headache during pregnancy: Etiologies and applicability of the ICHD-3 criteria

Introduction: Given the high prevalence of primary headache in the young population, and the rate of pregnancy in this age group, it is unsurprising that pregnant women present a high likelihood of consulting due to headache. Objectives: This study seeks to determine the main aetiologies and predictors of headache and the usefulness of the International Classification of Headache Disorders (third edition-beta; ICHD-3 beta) for differentiating primary from non-primary headaches in pregnant women at the emergency department. Patients and methods: We performed a cross-sectional study comparing the prevalence of patients meeting the ICHD-3 beta criteria, associated symptoms, history of headache, and demographic features between primary and non-primary headaches. Results: Headache was responsible for 142 out of 2952 admissions (4.8%). Headache was primary, non-primary, or unclassified in 66.9%, 27.4%, and 5.6% of cases, respectively. Migraine and headache associated with hypertensive disorders were the most frequent aetiologies for primary and non-primary headaches: 91.6% and 31.4% of cases, respectively. The factors associated with primary headache were fulfilling the ICHD-3 beta criteria (OR: 23.5; 95% CI, 12.5–34.5; p < 0.001), history of migraine (OR: 2.85; 95% CI, 1.18–5.94; p = 0.013), history of similar episodes (OR: 6.4; 95% CI, 2.78–14.0; p < 0.001), and description of phosphenes (OR: 4.2; 95% CI, 1.5–11.68; p = 0.02). The factors associated with non-primary headaches were fever (OR: 12.8; 95% CI, 1.38–119; p = 0.016) and mean arterial blood pressure greater than 106.6 (OR: 2.6; 95% CI, 1.7–3.5; p = 0.03). Conclusion: In our study, the ICHD-3 beta criteria were useful for differentiating primary from non-primary headaches in pregnant women. History of migraine, history of similar episodes, phosphenes, fever, and high arterial blood pressure were also valuable predictors.