Seizure Medications and Pregnancy: Risks of Birth Defects and Drug Interactions

When a woman with epilepsy becomes pregnant, she faces a difficult choice: keep taking her seizure medication to prevent dangerous seizures, or stop it to protect her baby - but risk losing control of her seizures. This isn’t just a medical dilemma. It’s a life-altering decision made every day by women who want to start a family but are caught between two serious risks.

Some Seizure Medications Carry High Risks During Pregnancy

Not all seizure medications are the same when it comes to pregnancy. Some are far more dangerous than others. The biggest red flag is valproate - also known as sodium valproate or valproic acid. Studies show that about 10% of babies exposed to valproate during pregnancy develop major physical birth defects. That’s five times higher than the general population risk of 2-3%. These defects can include heart problems, cleft lip or palate, spinal cord issues, and microcephaly - where the baby’s head is smaller than normal.

Valproate doesn’t just affect physical development. Children exposed to it in the womb are more than twice as likely to be diagnosed with autism spectrum disorder (ASD) and nearly twice as likely to have attention deficit hyperactivity disorder (ADHD), according to research from Indiana University published in Neurology in 2020. Because of this, health agencies like the UK’s MHRA and the American Epilepsy Society now strongly advise against using valproate in women of childbearing age unless there’s absolutely no other option.

Other high-risk medications include carbamazepine (Tegretol), phenytoin (Epanutin), phenobarbital, and topiramate (Topamax). These drugs also increase the chance of physical birth abnormalities, though not as severely as valproate. The risk rises with higher doses - especially for carbamazepine, phenobarbital, and valproate. For example, women taking more than 1,000 mg of valproate daily have nearly double the risk of birth defects compared to those on lower doses.

Safer Alternatives Exist - And They Work

The good news? Not all seizure medications are risky. Two drugs - lamotrigine (Lamictal) and levetiracetam (Keppra) - have been consistently shown to be much safer during pregnancy. A 2023 review by the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) found no significant increase in birth defects linked to these two medications. They’re now considered first-choice options for women planning pregnancy.

A major Stanford University study published in JAMA Neurology in 2021 followed 298 children whose mothers took lamotrigine or levetiracetam during pregnancy. At age two, these children showed normal verbal development - no different from children whose mothers didn’t take any seizure medication. While there was a slight increase in minor developmental delays at the highest exposure levels, the overall picture is reassuring.

Since the 1990s, the rate of major birth defects linked to seizure medications has dropped by 39%, according to data from JAMA Neurology in 2024. That’s not because the drugs changed - it’s because doctors are prescribing safer ones more often. More women are getting preconception counseling. More are switching from valproate to lamotrigine or levetiracetam before they even get pregnant.

Drug Interactions Can Undermine Both Birth Control and Seizure Control

Here’s something many women don’t realize: seizure medications can interfere with birth control - and birth control can interfere with seizure medications. It’s a two-way street.

Drugs like carbamazepine, phenytoin, phenobarbital, and high doses of topiramate and oxcarbazepine speed up how fast your body breaks down hormones. That means birth control pills, patches, or rings may not work as well. Women on these medications have a higher chance of unintended pregnancy - even if they take their pill every day.

On the flip side, hormonal birth control can lower the levels of certain seizure medications in your blood. That’s especially true for lamotrigine, valproate, zonisamide, and rufinamide. If your lamotrigine level drops too low, you could start having seizures again. That’s dangerous - not just for you, but for your baby.

That’s why women on seizure meds need to talk to their doctor about birth control options. Intrauterine devices (IUDs), implants, or progestin-only injections are often better choices than pills. If you’re on lamotrigine and need hormonal birth control, your doctor may need to adjust your dose - and monitor your blood levels closely.

Uncontrolled Seizures Are More Dangerous Than Medication

It’s easy to think, “If the medicine is risky, maybe I should just stop it.” But that’s not safe. Uncontrolled seizures - especially tonic-clonic (grand mal) seizures - can cause miscarriage, premature birth, injury to the mother, or even fetal death. The physical trauma from a fall during a seizure can harm the baby. Oxygen deprivation during a long seizure can damage the fetal brain.

As neurologist Kelsey Wiggs from Indiana University put it, women with epilepsy face an “excruciating double bind.” They need medication to stay safe - but the safest medication for them might not be the safest for their baby.

Experts agree: no seizure medication is as dangerous as uncontrolled seizures. The American Epilepsy Society says the goal isn’t to stop all meds - it’s to use the lowest effective dose of the safest possible drug. Stopping medication without medical guidance is one of the most common mistakes women make before or during pregnancy.

Who’s Still at Risk? And Why

Even though safer options exist, not everyone gets them. A 2023 French study found that women with lower income, less education, or limited access to specialists were more likely to be prescribed high-risk drugs like valproate during pregnancy. This isn’t because doctors are careless - it’s often because they don’t have time, resources, or training to manage complex cases.

Women in rural areas, those without insurance, or those who see multiple doctors without coordination are at higher risk. They may not get preconception counseling at all. Some don’t even know their medication could affect their baby. A 2023 survey from AESNET found that two-thirds of women of childbearing age with epilepsy answered basic questions about medication safety and birth control interactions incorrectly.

That’s why preconception planning matters so much. If you’re thinking about getting pregnant - even if it’s years away - talk to your neurologist now. Don’t wait until you’re already pregnant. Switching medications takes time. Doses need to be adjusted slowly. Blood levels need to be monitored. You need a plan.

What You Should Do Right Now

If you’re a woman with epilepsy and you’re sexually active:

1. Ask your doctor which medication you’re on and whether it’s considered high-risk for pregnancy.
2. If you’re on valproate, carbamazepine, phenytoin, phenobarbital, or high-dose topiramate, ask about switching to lamotrigine or levetiracetam - even if you’re not planning to get pregnant yet.
3. Use reliable birth control. Avoid pills, patches, or rings if you’re on enzyme-inducing medications. Ask about IUDs or implants.
4. If you’re trying to get pregnant, schedule a preconception visit with your neurologist and OB-GYN. Bring your full medication list.
5. Don’t stop or change your meds without medical advice. Seizures are a real and immediate danger.

If you’re already pregnant and taking seizure medication: do not stop. Call your doctor immediately. They may need to adjust your dose, check your blood levels, or switch you to a safer drug - but only under supervision.

Hope Is Real - But Planning Is Essential

Today, women with epilepsy have more options than ever before. The risk of birth defects has dropped significantly. More doctors know how to manage epilepsy in pregnancy. Safer drugs work just as well as older ones. Many women go on to have healthy babies without any complications.

But this doesn’t happen by accident. It happens because women plan ahead. Because they ask questions. Because they get the right care before conception - not after.

Having epilepsy doesn’t mean you can’t have a child. It means you need to be smarter about how you manage it. The goal isn’t to avoid medication - it’s to choose the right one, at the right dose, at the right time.