Acute, severe headache in a pregnant woman is a “red flag,” especially if she has high blood pressure and no prior history of headache. She could be at risk for preeclampsia or other pregnancy complications, so neuroimaging and monitoring are warranted, according to a new study—the largest of its kind—published online August 19, 2015, in Neurology. The study’s findings offer the first clinical recommendations for making diagnostic decisions about headaches in pregnant women.
“Headaches during pregnancy are quite common, but it is not always easy to distinguish between a recurring, preexisting migraine condition and a headache caused by a pregnancy complication,” said lead author Matthew S. Robbins, MD, director of inpatient services at Montefiore Headache Center, chief of neurology at Jack D. Weiler Hospital of Montefiore, and associate professor of clinical neurology at Albert Einstein College of Medicine of Yeshiva University in Bronx, NY.
“Our study suggests that physicians should pay close attention when a pregnant woman presents with a severe headache, especially if she has elevated blood pressure or lack of past headache history," Dr. Robbins said. "Those patients should be referred immediately for neuroimaging and monitoring for preeclampsia.”
In this retrospective study, researchers analyzed records of every pregnant woman with headache who had been referred for a neurological consultation at Weiler Hospital over a 5-year period. The study involved 140 women with an average age of 29. A large majority of the patients were Hispanic or African-American, reflecting the makeup of the Bronx population.
Most of the women (65%) had primary headaches, 91% of which were migraines. Among the 35% patients with secondary headache, about half of these (51%) were diagnosed with pregnancy-related high blood pressure, including nearly 39% who had preeclampsia.
The most telling indicator of a secondary headache among pregnant women proved to be high blood pressure (defined as systolic blood pressure ≥140 mm Hg or a diastolic blood pressure ≥90 mm Hg). Compared with pregnant women with headache but no high blood pressure, women with headache plus high blood pressure faced a 17-fold increased likelihood that their headaches were caused by some other condition. "In most of these patients, their elevated blood pressure was driven by preeclampsia," Dr. Robbins said.
Another sign to be taken seriously, the authors wrote, is lack of a previous history of headache, which was associated with a five-fold increased likelihood that the headache was secondary to something else.
Other warning signs were fever, seizures, headache in the absence of phonophobia (sound sensitivity), and psychiatric problems.