Couples where one or both partners are affected by epilepsy may ask for advice on the risk that their offspring may develop epilepsy, as well as issues around the use of anti-epilepsy drugs (AEDs) in pregnancy.
The aim is to keep the woman seizure free during the pregnancy, whilst trying to reduce the possible risk of damage to the fetus from AEDs.
For women taking AEDs which affect the metabolism of folate, a higher dose of folate (5mg) is recommended to reduce the chance of spina bifida. There are general discussions to be made by the GP, but referral to a specialist in epilepsy and possibly to a genetic counsellor should be strongly considered.
If a woman with epilepsy has an unplanned pregnancy she should be advised not to stop her AEDs, but issues around AEDs and use of folate (possibly at higher dose of 5mg daily) should be clarified with a epilepsy specialist. The risk of AEDs affecting the fetus are greatest in the first trimester.
If a woman has simple or complex partial, absence or myoclonic seizures in pregnancy there is no evidence that this will harm the baby. Those having tonic-clonic seizures in pregnancy are at slightly higher risk of causing harm to the baby. The risk is still very low, especially if the seizures are infrequent.
Genetics
There are many different types and causes of epilepsy. In 60% of people with epilepsy there is no known or identifiable cause. In the 40% with an identifiable cause this can be because of a previous insult to the brain such as trauma, infection, stroke or because of an inherited susceptibility.
There are three ways in which epilepsy can be inherited:
- A low epilepsy seizure threshold may be inherited.
- It can be inherited as a symptom of an inherited genetic condition such as Tuberous sclerosis.
- There are certain types of epilepsy where a family history has been identified. These include Benign Rolandic Epilepsy, Juvenile Myoclonic Epilepsy and Temporal Lobe Epilepsy.
For the vast majority of seizures, the risk of the children having seizures is higher if the mother has epilepsy rather than the father. Risk of developing seizures for the children of fathers with epilepsy is only slightly higher than the general population risk. The reasons for this are unknown and are not related to the seizure frequency or to the AEDs the mother took in pregnancy.
Certain types of epilepsy do seem to have different risks for children developing seizures. The risk for unprovoked seizures is higher in children whose parents developed epilepsy before age 20 yrs (9 % risk), than in children whose parents developed epilepsy after the age of 20 yrs (3%). The risk is higher in children whose parents have a history of absence seizures (9%) compared to those with generalised (3%) or partial (5%) seizures.
