Hormonal factors affect migraine headache intensity during pregnancy, but not the frequency of migraine attacks, according to a recent study published in The Journal of Headache and Pain.
The study was a longitudinal population-based analysis within the Akershus Birth Cohort study, which gathered information on all women scheduled to give birth at the Akershus University Hospital, Oslo, Norway. Enrollment in the study targeted women attending a routine ultrasound at week 17, from November 2008 to April 2010, and 4662 women who qualified for participation gave consent for inclusion at this point. Data were compiled from self-completed questionnaires at weeks 17 and 32, and 8 weeks after delivery. Response rates declined at each point in the study, and a total of 1981 women returned all 3 questionnaires. Of these, 17.1% (n=338) had active migraine, but 58 had to be excluded due to chronic headache, as the presence of over 14 attacks per month would make it impossible to accurately track the effects of hormonal fluctuations on migraine.
Of the remaining 280 women included in the study sample, 18.6% (n=52) self-reported experiencing menstrual migraine, and 81.4% (n=228) reported non-menstrual migraine. Headache frequency was high for both groups prior to pregnancy and during the first half of pregnancy, and both groups experienced improvement in headache frequency in the latter half of pregnancy, followed by slightly more frequent attacks directly after giving birth. The menstrual migraine group experienced higher levels of pain than the non-menstrual migraine group, with the highest intensity occurring early in pregnancy, improving in the second half, and then worsening again immediately post-partum.
Study investigators conclude that “[hormonal] factors and [pre-menstrual syndrome] did not affect frequency of headaches, but may affect the headache intensity during pregnancy in female migraineurs. We suggest that an individual treatment plan for migraines during pregnancy is needed especially for those women with the highest symptoms load.”
Petrovski BE, Vetvik KG, Lundqvist C, Eberhard-Gran M. Characteristics of menstrual versus non-menstrual migraine during pregnancy: a longitudinal population-based study. J Headache Pain. doi: 2018; 19(1):27.