Secondary Headaches During Pregnancy: When to Worry

Headaches in pregnancy are a frequent cause of worry for both patients and healthcare providers. Physiological changes during this period increase the risk of a number of secondary headache disorders, and often also have an impact on primary headache disorders. This article reviews recent research into distinguishing worrisome vs non-worrisome headache presentations during pregnancy.

Recent research suggests that secondary causes of headache are highly prevalent during pregnancy, in between 25 and 42.4% of women seeking medical attention. Secondary causes of headache in pregnancy are most commonly homeostatic disturbances and hypertensive disorders of pregnancy, vascular problems, space-occupying lesions, and infections. Migraine itself also increases the risk of hypertensive disorders of pregnancy. Specific red flags for a secondary cause of headache in pregnancy include absence of any headache history, more severe pain, systemic features such as elevated blood pressure, and abnormal laboratory tests including thrombocytopenia or thrombocytosis, elevated liver function tests, elevated C-reactive protein, or proteinuria, in addition to traditional red flags, such as a change in headache pattern. Secondary causes of headache are common in women seeking medical attention during pregnancy. Red flags for secondary causes of headache during pregnancy may be remembered with the mnemonic PREGNANT HA (proteinuria, rapid onset, elevated blood pressure or temperature, gestational age in third trimester, neurological signs or symptoms, altered level of consciousness, no headache history or known history of a secondary headache disorder, thrombocytopenia or thrombocytosis, high liver function tests or CRP, or agonizingly severe pain). Increased education of patients and their providers may help improve selection of patients for workup of a secondary cause.