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on a higher dose combined OCP, efficacy may be reduced. Breakthrough bleeding occurring
in the middle of a cycle of contraceptive use is generally due to a relative oestrogen deficiency
and usually taken as a sign of incipient failure of contraception. However, pregnancy rates
(approximately 7% per year) still appear to be lower compared with barrier methods which
have a failure rate of between 15 and 20%.

Levonorgestrel implants have an increased failure rate in women taking enzyme-inducing
AEDs44, and although the data are not available it can only be assumed that the efficacy of
progesterone only OCPs is also reduced. Medroxyprogesterone injections may be effective
in women with epilepsy, with their elimination being dependent on hepatic blood flow instead
of hepatic metabolism, but data proving this are not as yet available. Whether the dose of the
morning-after pill should be changed in those on enzyme-inducing drugs is unknown.

Of note, OCPs can reduce the levels of lamotrigine and to a clinically significant level45.

Pregnancy

The management of pregnant women with epilepsy is becoming of increasing importance as
the risk factors for adverse outcomes of pregnancy become more clearly delineated46. The
majority of women with epilepsy will have a normal pregnancy and delivery, an unchanged
seizure frequency and over a 90% chance of a healthy baby. However, considering the
prevalence of epilepsy many pregnancies are still at risk for an adverse outcome. Because of
this, pregnancies in women with epilepsy are considered high risk and need careful
management by both medical and obstetric teams.

Preconception
Preconception counselling should be available to all women with epilepsy contemplating a
pregnancy. This should start at the time of diagnosis and at subsequent reviews. While it may
not always be appropriate to discuss the many relevant issues (for example in paediatric
practice) it should certainly be considered in female adolescents with epilepsy, including
those whose care is being transferred from a paediatrician to an adult physician. The fact that
the relevant issues have been discussed should always be clearly recorded in the notes.
Women with epilepsy of childbearing years do not always recall being given relevant
information, hence the need to repeat this regularly. For example, the results of a postal
survey of women showed that only between 38 and 48% recalled being given information on
contraception, pre-pregnancy planning, folic acid and teratogenicity47.

Ideally an organised joint obstetric/neurology preconceptual counselling service should be
available to allow rapid assessment of women actively contemplating pregnancy and to
coordinate care during pregnancy. At present, given the numbers of neurologists and those
other specialists with an interest in epilepsy, this is not always available and waiting times
are long. Nevertheless, a re-configuration of clinics and additional resources to allow for this
service should be actively considered.

During counselling a re-evaluation of the diagnosis and the need for continued antiepileptic
medication should take place. Consideration should be given to the AED and indeed the
dosage of any AED that is prescribed. The risks and benefits of reducing or changing
medication should be fully discussed with each individual patient. That the risk of major
congenital malformations is at least doubled to trebled (49%) in women receiving AEDs,
compared with the general population (23%) must be discussed. Details of particular
malformations occurring with specific AEDs, with the levels of risk (where known), should
also be mentioned. As well as major malformations the risk of cognitive and developmental
delay should also be discussed.