Treating Epilepsy in Pregnancy

Suzan, a married 27-year-old with epilepsy, well under control with medication came to me recently. She asked me if she can get pregnant and what to expect during her pregnancy in terms of medication and seizures. You too could have similar questions.

First, the reassuring news is you can carry a normal pregnancy if your seizures are well under control. However, we may need to make slight adjustments in medication as the pregnancy progresses.

Preparing for a healthy pregnancy with epilepsy

Epilepsy is a chronic condition that manifests as recurrent, unprovoked seizures. It can affect people of all ages. Epilepsy can be easily controlled with the right medication. Since it is a chronic condition, it needs long-term medication.

Preparing for pregnancy must begin years before conception. Epileptic women of child-bearing age must take special precautions as they can become pregnant at any time. As the first step, they are put on anti-epileptic medication that is safe during pregnancy. In the past, we did not know which medication could cause harmful effects to the unborn baby. But with research and advances in modern medicine, we know what medication is safe to prescribe.

Second, we give all women of child-bearing age a daily dose of folic acid. By this, we build up stores of folic acid in the woman’s body. If she gets pregnant, she has enough stores to nourish her baby.

Pregnancy and Epilepsy

Can epilepsy make for a difficult pregnancy? The best indicator of how you’ll do during pregnancy in terms of seizures is the last 9 months before pregnancy. It is important to discuss your last 9 months with your doctor before pregnancy because having generalized seizures during pregnancy can have bad outcomes and even result in an featal death.

Because of these reasons, epilepsy is considered a high-risk pregnancy. Epileptic women should therefore follow up closely with a neurologist and an experienced obstetrician and gynecologist.

Medication Changes in Pregnancy

Your antiseizure medication is modified in pregnancy. During pregnancy, your body undergoes many changes. There is increased blood flow to your kidneys and an increased glomerular filtration rate. As a result, drugs get eliminated faster from your body. The drug concentration in your blood is much less and therefore the effect of the drug is less. Levetiracetam, lamotrigine, and lacosamide have the most reduced drug concentrations in blood during pregnancy.

It is recommended to get the blood levels of antiseizure medication at the beginning of pregnancy then monitoring them closely. We increase the medication every 2-3 months to maintain optimum drug concentrations in blood for a safe and successful pregnancy.

Pregnancy-Safe Antiseizure Drugs and Effects on the Baby

The effect on the baby due to antiseizure drugs can be measured with two factors-

• A major congenital malformation- any birth defect or abnormal shape of an organ. E.g.: cleft lip, neural tube defects. This is 1-3% in the normal population.
• Cognitive effects- any effect on the baby’s IQ and cognitive function.

In the past, we did not have sufficient data to determine what antiepileptic drugs were harmful to the baby. But thanks to the hard work of many research teams around the world working in pregnancy registries following women taking antiseizure medication and checking pregnancy outcomes we have a clearer idea.

Research shows the safest antiepileptic medication during pregnancy is levetiracetam, lamotrigine, and oxcarbazepine with a risk to the baby of 1-5% which is slightly higher than the 1-3% in a normal population. Medications like carbamazepine, phenytoin, and phenobarbital have a slightly higher risk ranging from 1-7%.

Medication like topiramate can cause cleft lip and should be avoided as much as possible for epilepsy during pregnancy and avoided completely for migraine during pregnancy.

Sodium valproate is completely contraindicated in pregnancy. It has a very high risk for fetal malformation (up to 14%) and can also cause cognitive issues. It drops the IQ of the baby by 7-10 points and can cause autism and ADHD in children.

Specific risks of various drugs in pregnancy-

• Levetiracetam- 0.7 - 3.5%
• Lamotrigine- 1.5% - 4.9%
• Oxcarbazepine- 2.2% - 5.3%
• Carbamazepine- 2.6% - 5.9%
• Phenytoin- 2.3% - 6.4%
• Zonisamide- 0-13% (average 2.9%)

The effect of these drugs is dose-dependent. The higher the dose the more the effect on the baby. If you use more than one medication too, the effect on the baby is higher than when using a single medication.

Conclusion 

We have not uncovered whether the newer medication causes autism or major congenital malformations in babies. It is important to participate in these registries to help with new scientific discoveries. We are thankful to women all over the world who have participated in these studies to bring new information to light.  

It is possible to carry a pregnancy to term safely and deliver a healthy baby with epilepsy as long as it is under control. Join us next time to learn more about epilepsy and breastfeeding.