Clinicians are understandably concerned when a pregnant patient describes headache. Onset, duration, positional worsening, and accompanying features all figure into understanding the pathophysiology and making a determination for proper evaluation and subsequent treatment. Most concerning is the patient who has never had headache prior to the pregnancy who is now presenting with new and severe pain. Three illustrative actual cases will highlight salient features.

Neurologists approach a chief complaint of headache with meticulous wariness. The majority of headaches are benign, meaning that the pain is primary (without concerning secondary cause). Examples of primary headache include migraine and tension-type headache. Migraine is very common, affecting 18 % of American women. The condition is most common in women of childbearing age; migraine prevalence decreases postmenopause. It is genetic, with the predisposition running in families, and, often, patients can recall an elderly family member who had “sick headache” even if not formally diagnosed with migraine. The International Headache Society (IHS) has specific guidelines for making the diagnosis. A person must have at least five attacks lasting between 4 and 72 h of moderate to severe intensity, unilateral and throbbing in nature, accompanied by nausea or vomiting, or light and sound sensitivity. Patients often feel that if the headache is not excruciating, then it cannot be a migraine. An accurate diagnosis prior to pregnancy is helpful; migraine incidence decreases substantially during pregnancy. If a migraine patient who has been stable throughout the pregnancy describes a worsening in the third trimester, this should prompt a careful evaluation.

Tension-type headache, formally called “muscle contraction headache” or “hatband headache,” is quite common. IHS criteria define this phenotype as a headache, which is bilateral, squeezing, or pressing in description, mild to moderate intensity, with few other associated features. Fatigue, muscle spasm, and stress can certainly trigger a tension-type headache, and often rest alone is enough to let the pain improve. Patients are usually able to complete their regular tasks despite a tension-type headache; it is worth recognizing this description, as these headaches are far less worrisome.

A patient describing a new and different headache is concerning. Headaches that are explosive in onset may represent CNS bleeding, such as aneurysm rupture. These are the “thunderclap” headaches. If a patient describes an acute onset with any sort of change in consciousness, she should be directed to emergency evaluation at once. Headaches that are worse with bending over, positional, accompanied by focal numbness or weakness, vertigo, or diplopia (double vision) are also worrisome and should be promptly evaluated. “New and different” or “first or worst” are useful monikers.

Headache evaluation includes a detailed history with documentation of the start and frequency of the headaches, as well as any specific characteristics. Neurologic exam is essential; any focality or sign of increased intracranial pressure such as abnormal funduscopic exam requires further evaluation. Any concern for preeclampsia would of course prompt immediate evaluation.

During pregnancy, radiation should be avoided if possible especially during the first trimester although exposure to the fetus from a non-contrast head CT is less than 0.01 rad. The American College of Radiology states that pregnant women can undergo MRI imaging at any stage of pregnancy; it is a risk-benefit decision and should be performed only if absolutely necessary. There is very little data about gadolinium contrast safety, and contrast should be avoided if possible. MRI, MR angiogram, and MR venogram can all be performed without contrast. The neurologist and obstetrician should consult and make appropriate recommendations, explaining potential fetal risk, to the mother. If the evaluating neurologist has concern for a secondary cause of headache, it may well be necessary to image.

Once the patient has been diagnosed, treatment discussion should also be a joint process. Minimizing medication is important whenever possible, but if the mother’s disability from even a nonconcerning headache diagnosis such as migraine is great enough to impair her ability to function, medication may be necessary. Depending on the level of fetal development, there may be more options. Some of these will be discussed below. Acupuncture, biofeedback, and cognitive behavioral therapy are options for patients; some of these treatments are covered by health insurance. Massage may also help if the headache is considered secondary to muscle train; dry-needled trigger point injections can be an option as well.