OnabotulinumtoxinA treatment for chronic migraine in pregnancy: An updated report of real-world headache and pregnancy outcomes over 14 years in Hull.

BackgroundOnabotulinumtoxinA is widely used for patients with chronic migraine, but its safety and efficacy in pregnancy remain unclear. In 2020, we published a report of 45 subjects who became pregnant on OnabotulinumtoxinA treatment for chronic migraine. Although numbers were small, the results suggested that OnabotulinumtoxinA treatment was effective in pregnancy without evidence of adverse pregnancy outcome. We now have an additional 81 subjects to add to the database.MethodThis is a tertiary centre (Hull) prospective study between 2010-2024. Subjects who became pregnant during treatment with OnabotulinumtoxinA for chronic migraine were recruited. Subjects were provided informed consent whether to continue treatment with OnabotulinumtoxinA. All subjects were followed up 12-weekly with headache and pregnancy outcomes collected.ResultsBetween 2010-2024, 126 subjects became pregnant during OnabotulinumtoxinA treatment for chronic migraine. Of these, 97/126 (77.0%) opted to continue treatment with OnabotulinumtoxinA. All 97/97 (100.0%) subjects who continued OnabotulinumtoxinA treatment remained in migraine remission, compared to only 9/29 (31.0%) who discontinued treatment. 2/97 (2.1%) subjects who continued treatment suffered miscarriages whereas 1/29 (3.4%) subjects who discontinued treatment suffered a miscarriage. No foetal malformations were reported.ConclusionIn our small descriptive study, subjects who continued OnabotulinumtoxinA in pregnancy continued to have migraine remission with no adverse pregnancy outcomes in our cohort.