Gynecology

Which Drug for the Pregnant Woman with Epilepsy?

Key points –Learning bite

More than 90 percent of pregnant women who have epilepsy deliver healthy babies.

Does epilepsy change during pregnancy?
Every woman reacts to pregnancy differently. For most pregnant women who have epilepsy, seizures remain the same. For a few, seizures become less frequent. For others — particularly women who have poorly controlled epilepsy — pregnancy increases the number of seizures.

How does epilepsy affect pregnancy?

Higher risk of pregnancy-related complications, including:
Severe morning sickness
Anemia
Vaginal bleeding
placental abruption
preeclampsia
Premature birth
uncontrolled seizures may deprive the baby of oxygen. Seizures can also increase the risk of miscarriage or stillbirth.


What about medication?
Birth defects — including cleft palate, neural tube defects, skeletal abnormalities, and congenital heart and urinary tract defects — are a major concern with seizure medications.
For babies whose mothers take seizure medication, the risk of birth defects is 4 to 8 percent.

More recent research consistently indicate that the risk of major congenital malformations is two to four times as high with the use of valproate as with the use of other antiepileptic drugs such as carbamazepine and lamotrigine. Carbamazepineappears comparatively safe with respect to malformations .

A trial of lamotrigine could be considered, since malformation rates associated with its use are similar to those associated with the use of carbamazepine. However, lamotrigine is difficult to use in pregnancy because of the risk of breakthrough seizures.

Cognitive development of a child may be affected by exposure throughout pregnancy.

Children exposed to valproate in utero had significantly lower IQs

Babies born to mothers who have epilepsy also have a slightly higher risk of developing seizures as they get older.


The safety of topiramate and levetiracetam, other newer-generation antiepileptic drugs with efficacy in generalized epilepsies, has not been sufficiently assessed for use during pregnancy.
A low dose of valproate remains an option if seizures cannot be controlled by other drugs. Doses below 800 mg per day may not be associated with fetal risks that are any greater than the risks associated with the use of other antiepileptic drugs

Because of the risks associated with a loss of seizure control during pregnancy, changes from valproate to another antiepileptic drug should be made and evaluated before conception.
By the time a woman realizes that she is pregnant, switching drugs is unlikely to reduce the risk of birth defects.

Because safe practice involves changing antiepileptic drugs only over a prolonged period (i.e., typically over a period of months, with the use of polytherapy during the transition period), a switch from valproate once pregnancy has been established is also unlikely to eliminate the risk of cognitive impairment in the child.


Folic acid helps prevent neural tube defects, serious abnormalities of the brain and spinal cord. Because some seizure drugs affect the way the body uses folic acid, a high-dose folic acid supplement is recommended.
Ideally starting three months before conception.

Babies who had mom's milk for more than 9 months had fewer seizures than babies who had breast milk for a shorter time, report the authors in the Journal of Pediatrics. Breast-feeding is encouraged for most women who have epilepsy, even those who take seizure medication.

In the November 30, 2010 issue of Neurology (Neurology 75 :(22) November 30, 2010) Meador and colleagues examined the cognitive outcomes of breastfed children of women with seizures enrolled in the NEAD study. Of 309 women with epilepsy, 42% of children ( total of 199) were breastfed.

Four antiepileptic drugs were studied including carbamazepine, lamotrigine, phenytoin and valproate.
This preliminary analysis failed to demonstrate any negative effects of breastfeeding during antiepileptic drug therapy on IQ of children who have been exposed to the medication by breast milk.

Breast feeding is not contraindicated. However, if the drugs are sedating, monitor the baby for sedation
Enzyme inducing anti-epileptic drugs can cause vitamin K deficiency in children born to women with epilepsy. Vitamin K (10 mg per day) can be prescribed in the last month of pregnancy. Alternatively, the baby should get 1 mg of vitamin K parenterally as soon as possible after labour.