[MI] Medicines and Pregnancy Registry - Antiepileptic use in females aged 0 to 54 in England: April 2018 to September 2022

Antiepileptics are important in controlling seizures and other epilepsy symptoms and untreated epilepsy in pregnancy can result in harm to the mother and child. However, use of some antiepileptic drugs during pregnancy has been associated with a range of harmful effects to the child. Valproate is a licensed treatment for epilepsy and bipolar disorder. It is associated with a significant risk of birth defects and developmental disorders in children born to women who take valproate during pregnancy. In 2018, following further evidence on the nature and magnitude of risks to the unborn child the MHRA advised that valproate must not be used in any woman or girl able to have children unless she is supported by a Pregnancy Prevention Programme (PPP). This is designed to make sure patients are fully aware of the risks and the need to avoid becoming pregnant.

In January 2021, the Commission on Human Medicine (CHM) published a review of the available safety data for antiepileptics during pregnancy. Their report concluded that data show that carbamazepine, phenobarbital, phenytoin, and topiramate are associated with an increased risk of major congenital malformations although data on the risk with some of these other antiepileptics are limited. They also highlighted data for topiramate, phenobarbital, and phenytoin that raises concerns that use of these products during pregnancy may be associated with poorer development outcomes in children, although available studies are limited for these as they are for other antiepileptics with regards to this risk. The report concluded that lamotrigine and levetiracetam are the safer antiepileptics to use during pregnancy. However, even for these medicines, data are not available to rule out a risk of neurodevelopmental disorders and delays. As of March 2023, cenobamate has been proactively included in the list of medicines monitored by the registry. This is due to the existing non-clinical data on the potential risks to the unborn child and their future development.

This report is to provide information on the prescribing of medicines in relation to pregnancies based upon data from the core register which has been developed to form the basis of the planned wider medicines registries and to identify limitations in the existing data sources.

It is important women do not stop taking their antiepileptic medicine without first discussing it with their doctor. Women receiving treatment who anticipate they may become pregnant at any point in the future are advised to discuss their treatment with a healthcare professional.