When to Worry About a Pregnancy Headache

A new study published in the journal Neurology offers guidelines for how to know if a headache during pregnancy is a sign of something serious—like preeclampsia.

When to Worry About a Pregnancy Headache luminaimages/Shutterstock

Headaches in pregnancy are very common, caused by everything from hormones and changes in posture to caffeine withdrawal. Occasionally, though, headaches can be an indication of a serious complication like preeclampsia, in which dangerously high blood pressure puts mom and baby in jeopardy. But how can you tell the difference? New research published this week in the journal Neurology looks at the causes of pregnancy headaches and offers new guidelines for how to diagnose them.

Spotting red flags

Doctors at Montefiore Health System and Albert Einstein College of Medicine in the Bronx, N.Y., analyzed the medical records of pregnant women with headaches over a five-year period. "We studied a large number of pregnant women presenting with severe headache attacks to the emergency and hospital setting," the study's lead author, Matthew S. Robbins, M.D., tells Fit Pregnancy. "We found that over one-third of the patients we evaluated had headache as a symptom of a separate underlying condition such as preeclampsia, rather than a more benign cause of headache such as migraine."

Headaches have already been known to be associated with preeclampsia. But the researchers also found other factors in the women who went on to be diagnosed with the condition. Those women who had high blood pressure in addition to a headache were 17 times more likely to have preeclampsia than those who didn't have high blood pressure. And women who didn't have a previous history of headaches were five times as likely to have an underlying condition. Knowing this can help doctors decide when to raise the red flag. "The presence of these factors in such patients may lead doctors to order diagnostic tests, such as a brain MRI, and monitor the patients closely for further signs of preeclampsia," Robbins says.

Don't be afraid to call your doctor

But if you develop a headache during pregnancy, how can you know if it's serious? If it's very bad or comes on suddenly, contact your doctor—and it's always better to be safe than sorry. "Any pregnant woman who experiences a severe headache should seek consultation with their doctor to make sure there are no worrisome causes, as well as to ensure their symptoms can be treated properly," Robbins says.

If you've been prone to headaches in the past, it can be a little more difficult to detect a problem, but you should still reach out for help. "In pregnant women who do have a history of past headache attacks, an attack lasting longer than usual was associated with more worrisome causes of headache," Robbins says. "The situation is also complex because migraine itself is a risk factor for the development of preeclampsia, which features headache as a cardinal symptom, so providers should be vigilant."

Although it's not known exactly why preeclampsia causes headaches, Robbins says it could be because of changes in the way blood circulates in the brain. Other signs of preeclampsia include blurred vision, abdominal pain and swelling, so if you have any of these in addition to a headache, call your doctor immediately. "Many of the symptoms of migraine and preeclampsia overlap, such as headache, nausea, vomiting, and visual changes, so it is important for pregnant women to follow up regularly with their provider if experiencing any of these symptoms," Robbins says.