Fortunately, migraines improve during pregnancy in the majority of women. None of the preventive drugs for migraine are approved by the FDA for pregnant women. The only medicine that is considered safe is a beta-blocker, metoprolol. Other drugs are either labeled as dangerous (e.g. topiramate and valproate) or as not having enough information about their effect on the fetus.
Most women obviously would rather not take any drugs. However, having frequent and severe migraines can be also detrimental to the fetus. It is not only the distress caused by severe pain but also the dehydration from vomiting that can have a negative effect.
A group of British doctors collected data over a 9-year period and have found 45 patients who became pregnant while receiving Botox for chronic migraines. All patients had received Botox within 3 months prior to the date of conception. 32 patients wished to continue treatment during pregnancy while the remaining 13 stopped treatment. There was one miscarriage in the treatment group. All other patients had full-term healthy babies of normal birth weight and no congenital malformations.
A recent poster presentation at the last annual meeting of the American Headache Society by neurologists at the Medstar Georgetown University Hospital in Washington, DC described 9 women treated with Botox during 10 pregnancies. All babies were born healthy.
This is a small number of patients and we cannot make any conclusions about the safety of Botox in pregnancy. Other reports, however, also suggest that Botox is safe.
In my 25 years of using Botox for migraines, I’ve given it to more than a dozen pregnant women. A few of them continued to receive Botox throughout more than one pregnancy.
Botox has been in use for over 30 years and millions of women have been treated with it with no reports of fetal problems. Unlike oral or injected drugs, it has only a local effect. The amount of Botox given for chronic migraines is measured in nanograms. After injections, it cannot be detected in the blood. All this suggests that Botox is safer than drugs taken by mouth or given by injection.
