ABSTRACT
Epilepsy is the most common major neurological disorder encountered by obstetricians, with one in 200 pregnancies occurring in women with epilepsy. Concerns these women may have include the worry that pregnancy will increase the risk of seizures, the effect of seizures on the pregnancy and fetus and whether medication will cause malformations in the child. Young women with epilepsy should be aware that pregnancy carries some additional risks for them as soon as they become sexually active. Some anti-epileptic drugs interact with oral contraceptives, but despite this combined oral contraceptives can be used by most women. The anti-epileptic drugs which induce liver enzymes, carbamazepine, phenytoin, phenobarbitone, primidone and topiramate, increase the rate of metabolism of both oestrogens and progestogens and this may lower blood concentrations to levels at which they are ineffective. An alternative regime that may be useful in some women is the three monthly or ‘tricycle’ system.
