- Whether and how to use lamotrigine in pregnancy is an individual decision made with your OB and the neurologist or psychiatrist who manages your care.
- MotherToBaby reports that several studies of thousands of pregnancies found no increased chance of birth defects with lamotrigine.
- Stopping suddenly can be dangerous: uncontrolled seizures, or a return of bipolar symptoms, can harm both the pregnant person and the pregnancy.
- Blood levels of lamotrigine often fall during pregnancy as the body clears it faster, so doses may need close monitoring and adjustment by your specialist.
- Doses that were raised in pregnancy often need to be brought back down after delivery, guided by your clinician.
- Lamotrigine passes into breast milk; breastfeeding decisions should be made with your care team.
If you take lamotrigine, often known by the brand name Lamictal, for epilepsy or bipolar disorder and you are pregnant or planning to be, you may be weighing two worries at once: the effect of the medicine on your baby, and what could happen if you stopped it. Both matter, and the safest path runs through your care team, not around it. This article gathers what leading sources say so you can have a more informed conversation with the clinicians who manage your pregnancy and your condition. It is general education only and is not a substitute for that conversation.
What lamotrigine is and what it treats
Lamotrigine is a medication used to treat some types of seizures (epilepsy), bipolar disorder, and Lennox-Gastaut syndrome, a severe form of epilepsy. It is an anticonvulsant that helps stabilize electrical activity in the brain. Because it is used for two very different kinds of conditions, the reasons a person needs it, and the risks of going without it, can look different from one patient to the next.
What the guidance says about lamotrigine in pregnancy
MotherToBaby, a service of the non-profit Organization of Teratology Information Specialists, provides a helpful plain-language summary of the evidence.
Birth defects
The overall picture is fairly reassuring for an anticonvulsant. MotherToBaby reports that several studies involving thousands of pregnancies have found no increased chance of birth defects with lamotrigine use during pregnancy. It notes that one study suggested a small (less than 1%) increased chance of oral clefts, such as cleft lip or cleft palate, with first-trimester use, but that this finding was not confirmed by other studies. It is worth knowing that lamotrigine is often viewed more favorably in this respect than some other anticonvulsants, though the choice of medicine is always individual and belongs to your specialist.
Why stopping suddenly can be dangerous
This is the most important part of the article. For many people, the risks of leaving the underlying condition untreated are greater than the risks of the medicine. MotherToBaby explains that having a seizure while pregnant could be harmful to a pregnancy. It also notes that people with bipolar disorder who stop their medication are at increased chance of episodes of depression or mania that could be harmful to both the pregnant person and the pregnancy.
Because of this, do not stop or reduce lamotrigine on your own, even if you have just learned you are pregnant. It can be tempting to think that stopping is the “safe” choice, but for epilepsy in particular, uncontrolled seizures carry real dangers, and abruptly stopping an anticonvulsant can itself provoke seizures. Any change should be planned with the neurologist, psychiatrist, or other prescriber who manages your treatment, working together with your OB.
Blood levels can change during pregnancy
One feature of lamotrigine deserves special attention. Research shows that the body tends to clear lamotrigine faster during pregnancy, so blood levels of the drug often fall as pregnancy progresses, sometimes substantially, particularly in the second and third trimesters. When levels drop too low, some studies suggest the chance of seizures can rise. For this reason, specialists often monitor lamotrigine levels during pregnancy and may adjust the dose to keep the medicine working. This is a managed, supervised process. Just as importantly, doses that are increased during pregnancy often need to be reduced again after delivery, because clearance returns toward pre-pregnancy levels within a few weeks, and this “step-down” is guided by your clinician to avoid side effects. All of this is a strong reason to stay in close contact with your care team rather than adjusting anything yourself.
A note on drug “categories”
You may see older references sorting pregnancy medicines into letter categories such as A, B, C, D, and X. Those FDA letter categories have been retired. They were replaced with a narrative labeling system (the Pregnancy and Lactation Labeling Rule) that describes what is actually known from studies rather than assigning a single letter. If you find an old “category” for lamotrigine, treat it as outdated and rely on current guidance and your care team.
Planning ahead and folic acid
Because seizure and mood control is so important, decisions about anticonvulsants are ideally made before pregnancy where possible, so your specialist can review your regimen and plan monitoring. Clinicians managing epilepsy in people who may become pregnant also commonly discuss folic acid. If you are of childbearing age and taking lamotrigine, this is a good topic to raise with your prescriber, rather than starting or changing anything on your own.
Breastfeeding
MotherToBaby reports that lamotrigine passes into breast milk, and that the amount in breast milk is usually much lower than a dose that would be given to a baby directly to control seizures. Many people breastfeed while taking lamotrigine, but because babies can vary, this is a decision to make with your care team, who may suggest watching the baby for any unusual sleepiness, poor feeding, or rash. As always, confirm your plan with your own clinician.
When to call your OB or specialist
Contact your care team promptly if you have a seizure, notice a change in seizure frequency or type, experience a return of depression or mania or any thoughts of harming yourself, or develop a new rash (rashes with lamotrigine should always be reported quickly). Stay in touch about monitoring appointments during pregnancy. For questions about a specific medication exposure in pregnancy or breastfeeding, you can also call MotherToBaby at 1-866-626-6847. If you are in mental-health crisis, call or text 988 for the Suicide and Crisis Lifeline.
Frequently asked questions
Is lamotrigine safe to take while pregnant? MotherToBaby reports that several studies of thousands of pregnancies found no increased chance of birth defects. It is often viewed relatively favorably among anticonvulsants, but the right choice is individual and belongs to your specialist and OB.
Should I stop lamotrigine now that I’m pregnant? Not on your own. Stopping can lead to seizures or a return of bipolar symptoms, which can harm you and the pregnancy. Any change must be planned with your prescriber.
Why might my dose change during pregnancy? The body often clears lamotrigine faster in pregnancy, so blood levels can fall and seizures may become more likely. Specialists may monitor levels and adjust the dose, then step it back down after delivery.
I took lamotrigine before I knew I was pregnant. Should I worry? Try not to panic. The birth-defect data are broadly reassuring. Tell your OB and your prescriber, and keep taking the medicine as directed unless they advise otherwise.
Can I breastfeed while taking lamotrigine? Many people do. MotherToBaby notes the amount in breast milk is usually much lower than a dose given directly to a baby. Decide with your care team, and report any unusual symptoms in the baby.
What about folic acid? Folic acid is commonly discussed for people who may become pregnant while on anticonvulsants. Raise it with your prescriber rather than starting or changing anything yourself.
This article is general education, not medical advice, and must not be used to start, stop, adjust, or taper any medication on your own. Suddenly stopping some medicines can be dangerous. Always work with the prescriber who manages your care. In an emergency call 911; for mental-health crisis call or text 988.
Sources
- MotherToBaby (Organization of Teratology Information Specialists) — Lamotrigine (Lamictal) fact sheet.
- Peer-reviewed studies on lamotrigine clearance, falling serum concentrations, seizure risk, and therapeutic drug monitoring during pregnancy, located via PubMed/NCBI.