Migraines during pregnancy present risks for adverse maternal, newborn outcomes

Pregnancies complicated by migraines are associated with adverse outcomes for both women and their babies, according to a presentation at The Pregnancy Meeting.

“Migraines or severe headache are very common disorders of the nervous system, affecting approximately 20% of women in the United States at any given time,” Ayellet Tzur-Tseva, MD, MSc, a maternal-fetal medicine fellow in the department of obstetrics and gynecology at Jewish General Hospital, McGill University, Montreal, said during the presentation.

Calling it the third most common disease in the world, Tzur-Tseva also said that migraines are most active in women of reproductive age and a frequent cause of headache during pregnancy.

Ayellet Tzur-Tseva

“About 60% of migraines improve during pregnancy, especially in the second and third trimesters,” she said. “But it also can occur then for the first time.”

The researchers studied nearly 14 million pregnant women who gave birth between 1999 and 2015 based on data from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample (HCUP-NIS) U.S. database.

Using ICD-9 code 346, the researchers identified 51,736 women who also had a diagnosis of migraines — a prevalence of 37 per 10,000 deliveries. The prevalence of migraines in this population rose during the study period (P < .001), according to the researchers.

Preexisting health conditions such as diabetes, chronic hypertension and obesity were more common among women with migraines. Also, women with migraines were more likely to be smokers.

Adjusted analysis showed that women with migraines were more likely to develop:

• preeclampsia (adjusted OR = 2.04; 95% CI, 1.97-2.1; P < .0001);
• placenta previa (aOR = 1.43; 95% CI, 1.3-1.57; P < .0001);
• abruptio placenta (aOR = 1.16; 95% CI, 1.08-1.26; P < .0001);
• chorioamnionitis (aOR = 1.2; 95% CI, 1.13-1.27; P < .0001);
• preterm premature rupture of membranes (aOR = 1.17; 95% CI, 1.09-1.26; P < .0001);
• myocardial infarction (aOR = 2.57; 95% CI, 1.06-6.26; P = .0374);
• venous thromboembolisms (aOR = 2.37; 95% CI, 2.14-2.63; P < .0001);
• cerebrovascular attack (aOR = 11.24; 95% CI, 7.71-16.39; P < .0001); and
• postpartum hemorrhage (aOR = 1.36; 95% CI, 1.3-1.42; P < .0001);

These women were more likely to have a cesarean delivery (aOR = 1.16; 95% CI, 1.14-1.18; P < .0001) and experience maternal death (aOR = 1.83; 95% CI, 1.12-3; P = .0166) as well.

Babies born to mothers who experience migraines were at greater risk for prematurity (aOR = 1.35; 95% CI, 1.31-1.39; P < .0001), congenital anomalies (aOR = 2.5; 95% CI, 2.33-2.7; P < .0001) and intrauterine growth restriction (aOR = 1.37; 95% CI, 1.3-1.43; P < .0001).

The researchers noted that migraine involves the cerebrovascular system and autonomic dysfunction in addition to a wide range of ischemic vascular disorders. While hypertensive disorders and migraine share the same risk factors, the pathophysiology is still unclear.

Possible explanations for this relationship include hypercoagulability due to platelet hyperaggregation, decreased prostacyclin production, altered vasoreactivity and endothelial dysfunction, the researchers said, adding that pregnancy enhances this procoagulant state.

Patients with abnormal vascularization are more prone to migraines, the researchers continued, and will have higher risk for preeclampsia since their vascular pathology cannot compensate well during the stress of pregnancy.

This vascular pathology is related to cardiovascular disease during pregnancy puerperium, the researchers said, adding that hypertensive diseases during pregnancy are known risk factors for cardiovascular diseases. Migraines, especially those with aura, are associated with myocardial infarction, stroke and venous thromboembolisms as well, the researchers said.

“Our conclusion was that pregnancies complicated by migraines are associated with adverse outcomes for both women and their babies,” Tzur-Tseva said. “Close surveillance of women who experience migraines during pregnancy is recommended.”