The incidence and etiology of postpartum headaches: a prospective cohort study

Purpose: We sought to determine the incidence, etiology, characteristics and risk factors for all headaches in the first week postpartum. Methods: This was a prospective cohort study of 985 women delivering over a three-month period in a single tertiary-care institution. These women underwent a structured interview and follow-up to collect demographic data and to assess for the presence and characteristics of postpartum headache (PPHa) or neck/shoulder pain. All headaches were diagnosed using an algorithm based on the diagnostic criteria of the International Headache Society. Multivariate analysis was used to examine possible risk factors. Results: Three hundred eighty-one of the 985 study participants (39%) reported headaches or neck/shoulder pain during the study period. The median time to onset of the PPHa was two days (0, 6; 1 st and 3rd quartiles) and duration was four hours (2, 24; 1 st and 3rd quartiles). Primary headaches accounted for > 75% of PPHa. Only a small number of headaches (4%) were incapacitating. Postdural puncture headache accounted for 4.7% of all PPHa. Significant risk factors for the development of PPHa were: known inadvertent dural puncture [odds ratio (OR)(adj) = 6.36; 95% confidence interval (CI) 1.29, 31.24]; previous headache history (1 - 12/yr-ORadj = 1.57; 95% CI 1.01, 2.44; > 12/yr-ORadj = 2.25; 95% CI 1.63, 3.11); multiparity (ORadj = 1.37; 95% CI 1.03, 1.82) and increasing age (ORd, = 1.03/yr; 95% CI 1.00, 1.06). Conclusions: Postpartum headaches are common, often first noted after discharge from hospital. The majority are related to primary headache disorders. Increased awareness of this epidemiological relationship and improved diagnosis of primary headache conditions may lead to improved headache-specific therapy and avoidance of unnecessary investigations or readmission to hospital.