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 and risk harm to herself and her baby. 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 Are Much Riskier Than Others

Not all seizure medications carry the same level of risk during pregnancy. The most dangerous drug is valproate (also called sodium valproate or valproic acid). Studies show that about 10% of babies exposed to valproate before birth develop major physical birth defects. These include heart problems, cleft lip or palate, spinal cord issues, and microcephaly (a smaller-than-normal head size). Valproate also raises the risk of autism and ADHD in children by more than double compared to other seizure drugs.

Other high-risk medications include carbamazepine, phenobarbital, phenytoin, and topiramate. Each of these increases the chance of physical birth abnormalities, though not as severely as valproate. For example, carbamazepine’s risk goes up with higher doses. The more you take, the higher the chance your baby will have a congenital malformation.

The good news? Not all seizure drugs are dangerous. Two medications-lamotrigine (Lamictal) and levetiracetam (Keppra)-have been shown to be much safer during pregnancy. A major review by the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) found these two carry the lowest risk of birth defects. Studies tracking children born to mothers who took lamotrigine or levetiracetam found normal development in language, motor skills, and behavior at age two. In fact, their development was nearly identical to children whose mothers didn’t take any seizure medication at all.

Drug Interactions Can Make Things Worse

Many women with epilepsy also use birth control. But here’s the problem: some seizure medications can make hormonal birth control (pills, patches, rings) much less effective. Drugs like carbamazepine, phenytoin, phenobarbital, oxcarbazepine, and high-dose topiramate speed up how fast your body breaks down hormones. This means you could get pregnant even if you’re taking birth control exactly as directed.

The reverse is also true. Hormonal birth control can lower the levels of some seizure drugs in your blood. This includes lamotrigine, valproate, zonisamide, and rufinamide. If your seizure medication drops too low, you might start having more seizures. That’s dangerous for both you and your baby.

This creates a dangerous cycle. A woman might be on a safe seizure drug like lamotrigine, but if she’s also using birth control pills, her seizure control could slip. Or she might be on a high-risk drug like carbamazepine, and the birth control isn’t working, leading to an unplanned pregnancy. A 2023 study found that nearly two-thirds of women of childbearing age with epilepsy answered basic questions about these interactions incorrectly. That’s alarming.

Uncontrolled Seizures Are the Real Danger

It’s easy to focus only on the risks of medication. But you have to remember: uncontrolled seizures are far more dangerous. A tonic-clonic seizure during pregnancy can cause miscarriage, premature labor, low oxygen to the baby, or even death. The American Epilepsy Society makes this clear: no seizure medication is as risky as having frequent, uncontrolled seizures.

That’s why experts don’t recommend stopping medication cold turkey. If you’re planning to get pregnant, you need to work with your neurologist months ahead of time. The goal isn’t to stop all drugs-it’s to switch to the safest one possible at the lowest effective dose. For many women, that means switching from valproate to lamotrigine or levetiracetam before conception.

Progress Has Been Made-But Not Enough

There’s real progress here. Between 1997 and 2011, the rate of major birth defects linked to seizure medications dropped by 39%. Why? Better prescribing. More awareness. More women getting preconception counseling. Newer drugs like lamotrigine and levetiracetam are now first-line choices for women of childbearing age.

But gaps remain. A French study found that women with lower income and fewer healthcare resources were still more likely to be prescribed high-risk drugs like valproate and phenobarbital. This isn’t about choice-it’s about access. Not everyone can see a specialist. Not everyone can afford to switch medications. Not everyone gets clear advice.

Even today, 11 other seizure medications don’t have enough data to say whether they’re safe during pregnancy. That means doctors are making educated guesses. That’s not ideal. We need more research, especially on long-term outcomes like learning, behavior, and IQ in children exposed to newer drugs.

What You Should Do If You’re Planning Pregnancy

If you’re a woman with epilepsy and you’re thinking about having a baby, here’s what matters:

1. Don’t wait until you’re pregnant to talk to your doctor. Start planning at least 6 months ahead.
2. Avoid valproate if possible. It’s the most dangerous option. If you’re on it now, don’t stop on your own-talk to your neurologist about switching.
3. Ask about lamotrigine or levetiracetam. These are the safest choices we have right now.
4. Review your birth control. If you’re using pills, patches, or rings, ask if your seizure meds are making them less effective. You might need a non-hormonal option like an IUD.
5. Take folic acid daily. A 4mg dose (higher than regular prenatal vitamins) before and during early pregnancy can reduce the risk of neural tube defects.

Many women worry that switching medications will cause more seizures. But studies show that with proper planning, most women maintain good seizure control on safer drugs. One study followed 298 children whose mothers took newer medications during pregnancy. Their language skills at age two were just as strong as children in the general population.

Hope Is Real-But It Requires Action

The idea that women with epilepsy can’t have children is outdated. We know better now. With the right care, most women with epilepsy have healthy babies. The key is preparation. It’s not about avoiding medication-it’s about choosing the right one.

There’s no perfect solution. Every drug has trade-offs. But the science is clear: the safest path forward isn’t to stop treatment. It’s to get smarter about what you’re taking-and when.