Aches and pains during pregnancy aren’t uncommon, but a new study suggests pregnant mothers may have cause to worry about headaches under certain circumstances.  

The researchers, from the Montefiore Health System and the Albert Einstein College of Medicine and Yeshiva University, have found that if a pregnant woman with high blood pressure and no history of headache then develops a headache that rapidly intensifies, she may be at risk for preeclampsia or other pregnancy complications. The research was published Wednesday in the journal Neurology, and the study authors said it is the largest study of its kind.

"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,” lead author Dr. Matthew S. Robbins, 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 Einstein, said in a news release. “Those patients should be referred immediately for neuroimaging and monitoring for preeclampsia."

An abnormal interaction of blood vessels that supply the placenta may cause preeclampsia, which usually occurs during a woman’s second or third trimester of pregnancy. According to the Mayo Clinic, preeclampsia is marked by high blood pressure and signs to other organs, usually the kidneys. The condition can be serious or fatal, and the only cure for pregnant mothers who are diagnosed with preeclampsia is delivering their babies.

Besides high blood pressure, symptoms of preeclampsia include headaches, blurry vision or abdominal pain, but some patients are asymptomatic.

Robbins and his team reviewed the medical records of every pregnant woman who reported having a headache and had been referred for a neurological consultation at Weiler Hospital over a five-year period. They selected 140 study participants whose average age was 29. According to the news release, the majority of the participants were Hispanic or African-American, which was consistent with the ethnic makeup of Bronx residents.

Ninety-one of the 140 participants had primary headaches, 90 percent of which were migraines. Forty-nine of the participants had a secondary headache, 51 percent of which had been diagnosed with pregnancy-related high blood pressure, including 38 percent of women who were diagnosed with preeclampsia.

They observed that women with headache and high blood pressure were 17 times as likely to have a headache caused by a different condition.  

"In most of these patients, their elevated blood pressure was driven by preeclampsia,” Robbins said in the news release.

Not having a history of headaches but having one that became increasingly severe during pregnancy was also associated with a five-fold increase chance that the headache was something else. Researchers noted that other signs of a potential pregnancy complication were seizures, fever, psychiatric problems, and headaches without sound sensitivity.