Pauline Anderson

April 19, 2016

VANCOUVER — Women who seek treatment for acute migraine during pregnancy go on to have rates of preeclampsia, preterm delivery, and low-birthweight babies that far exceed national averages, a new study suggests.

And being an older mother seems to be an independent predictor of these adverse delivery outcomes, the study showed.

"Over half the patients experienced some type of adverse birth outcome, which suggests that pregnancies in such patients should be considered high risk, especially in older women," said lead author Matthew S. Robbins, MD, associate professor, clinical neurology, Albert Einstein College of Medicine, chief of neurology, Jack D. Weiler Hospital, Montefiore Medical Center, and director of inpatient services, Montefiore Headache Center, Bronx, New York.

Dr Robbins presented his study here at the American Academy of Neurology (AAN) 2016 Annual Meeting.

Although migraine is fairly common among women of childbearing age, most women with migraine don't experience attacks during pregnancy. However, some do, possibly from lack of sleep, additional stresses, or other headache triggers, said Dr Robbins.

The new study included 90 pregnant women (mean age, 29.3 years) who presented to a Bronx hospital with acute migraine and received a neurologic consultation during the study: July 1, 2009, to June 30, 2014.

Many of the women (38.8%) were African American, which, according to Dr Robbins, is typical for the Bronx. Most were overweight or obese, with 76.7% having a body mass index of 30 kg/m2 or more. Almost a third of the group (30%) was nulliparous.

Aura "Over-Represented"

Migraine with aura "was very over-represented in the sample," at 40.7% of patients, commented Dr Robbins. Almost 13% of the group had a diagnosis of chronic migraine, and almost a third (31.4%) presented in status migrainosus.

Various intravenous and other therapies and interventions were used to treat these women, said Dr Robbins.

Researchers had delivery data on 79 of the 90 women (87.8%). They found that the rate of preeclampsia was 19.5% for the migraine sample compared with a national rate of 3% to 4%, said Dr Robbins.

The preterm delivery rate was 28.2%, or more than double the rate nationally (11.4%) or locally in the Bronx (11.7%), said Dr Robbins.

Also higher among the migraine group was the rate of low-birthweight babies: 19.2% compared with 8.0% for the national rate and 9.5% for the local rate.

Why these women have more negative pregnancy outcomes is unclear. "It's not yet known what makes such women with migraine more susceptible to such complications," commented Dr Robbins.

Contributing factors could include more "migraine comorbidity" and cardiovascular issues in women with these headaches. "Women with migraine have a higher rate of cardiovascular complications which may in part be genetic," said Dr Robbins.

Migraine may be associated with changes to the endothelium that could also play a role in preeclampsia, added Dr Robbins.  

Active migraine may affect maternal and fetal well-being, which could be yet another factor contributing to adverse outcomes, he said.

On the other hand, the rate of cesarean deliveries was slightly lower (30.8%) in the migraine group than the local (33.1%) or national (32.7%) rates. This is likely explained by preterm deliveries almost always being vaginal births, said Dr Robbins.

When the researchers pooled data, they found that being age 35 years or older predicted adverse delivery outcomes (odds ratio, 7.737; 95% confidence interval, 1.971 - 30.379; P = .003).

Having chronic migraine or status migrainous did not predict adverse delivery outcomes.

"It's hard to know if we should generalize this to other populations; this was done in an inner-city population who were overweight and had a history of pre-eclampsia," said Dr Robbins.

"Even so, this does suggest that if women have active migraine in pregnancy, maybe they should be followed quite closely during the pregnancy for complications later on."

Dr Robbins suggested that clinicians counsel women who are prone to migraine that the condition typically improves as the pregnancy advances.

Doctors might want to emphasize nonmedication approaches, such as relaxation techniques, biofeedback, and trigger avoidance, said Dr Robbins.

Also, they may want to recommend therapies that are safe in pregnancy, including nerve blocks with local anesthesia and devices recently approved by the US Food and Drug Administration, he said.

As well, Dr Robbins pointed out that acetaminophen and some antinausea medicines "have a long track record of safety and I'm fairly comfortable using them."

Although triptans are generally not used in pregnancy, a registry study from the company behind sumatriptan (GlaxoSmithKline) showed that the rate of birth defects is "quite similar" to that in the general population, noted Dr Robbins.

A limitation of the study was lack of a control group of women who had migraine but didn't present to acute care. Also, said Dr Robbins "we cannot attribute causality" to the medications or the therapies that the women had received earlier in their pregnancy.

Asked to comment on these findings was David J. Dickoff, MD, a general community neurologist in Yonkers, New York.

"The importance of the migraine study is to alert all doctors, especially obstetricians, that history of migraine headaches is a risk factor for pre-eclampsia," Dr Dickoff said. "These patients may need to be considered high risk and followed more closely for BP [blood pressure] elevations and proteinuria."

Jennifer Graves, MD, PhD, assistant professor, neurology, University of California at San Francisco, was one of the session coordinators.

The study, said Dr Graves, "highlights migraine as a potential risk factor for adverse events in pregnancy" and suggests that in these women, additional screening at routine visits may improve care.

"It is of interest for neurologists to help create migraine screening questions for our obstetric colleagues that may carry import for predicting these adverse events in pregnancy," said Dr Graves. "More prospective study of the value of these associations will be needed."

Dr Robbins receives compensation as section editor for Current Pain and Headache Reports and book royalties from Springer.

American Academy of Neurology (AAN) 2016 Annual Meeting. Abstract S26.008. Session I5; data blitz 15.003. Presented April 17, 2016.


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