Despite the fact that many women who suffer migraines find that the number and severity of these severe headaches decrease during pregnancy, migraines are now being linked to elevated blood pressure, abortions, caesareans, preterm births and babies with low birth weight.
This is documented by an extensive register-based study recently published in the scientific journal Headache and carried out at the Department of Clinical Epidemiology at Aarhus University and Aarhus University Hospital, Denmark.
"The study shows that pregnant women with migraine more often have complications in connection with their pregnancy and childbirth than women who don't suffer from migraine. Newborn babies whose mothers suffered from migraine during pregnancy also have an increased risk of complications such as respiratory distress and febrile seizures," says Nils Skajaa, BSc, who is the study's lead author. He is employed as a researcher at the Department of Clinical Epidemiology, Aarhus University and Aarhus University Hospital.
The researchers behind the study used the Danish health registers to identify more than 22,000 pregnant women with migraine who were in contact with a hospital as a result of their migraine or had received at least two prescriptions for migraine medication. The group was compared with an approximately ten times larger group of pregnant women without known migraine.
One finding in the study is that the risk of caesarean sections is between 15-25 per cent higher for pregnant women with migraine compared with pregnant women without migraine. Around twenty per cent of all births in Denmark are by caesarean section.
Researchers have also used the same data to deduce that migraine medication possibly prevents some of the complications. However, the results must be interpreted with caution, as Nils Skajaa explains:
"The study was not specifically designed to examine this aspect. However, we show that the risk of complications generally was lower for pregnant women with migraine who took medication when compared with the pregnant women with migraines who were not treated. This also indicates that the migraine medication isn't the cause of the complications, but rather the migraine itself. This is important knowledge for pregnant women with migraines," says Nils Skajaa.
Migraines are relatively common and affect twice as many women as men. The actual cause remains unknown, but previous research suggests that migraines may be triggered by stress, fatigue, or hormonal changes such as pregnancy.
"Paradoxically, women of childbearing age are particularly hard hit by migraines. Although experience shows that migraines become milder during pregnancy, this study emphasises that the healthcare service should be particularly aware of pregnant women with migraine," says Nils Skajaa.
About the study:
The study is a nationwide, population-based cohort study based on 22,841 pregnant women with migraine and 228,324 pregnant women without migraine identified between 2005 and 2012.
Most important partners: The biotechnology company Amgen Inc.
The study is financed by Amgen Inc.
Fei Xue and Osa Eisele, both employed by Amgen Inc, were some of the co-authors.