Synopsis
Integrate seizure control, fetal and parental reproductive safety, contraception interactions and pregnancy pharmacokinetics through planned specialist care while preventing abrupt antiseizure medicine withdrawal.
- Discuss pregnancy and contraception from the time antiseizure treatment is considered, because unplanned conception and interactions can occur years before someone volunteers a pregnancy intention.
- Refer anyone with epilepsy who is pregnant or planning pregnancy to an epilepsy specialist team and coordinate decisions with specialist obstetric, primary-care and pharmacy services.
- Do not stop antiseizure medicine abruptly after a positive pregnancy test; uncontrolled bilateral tonic-clonic seizures can harm both pregnant person and fetus, so changes require urgent specialist balancing.
- Use effective monotherapy at the lowest dose that maintains control where feasible, but avoid destabilising a previously successful regimen solely to meet a simplistic dose target.
- Valproate has major congenital and neurodevelopmental risks and requires the Pregnancy Prevention Programme for women and girls able to become pregnant; topiramate now has its own UK Pregnancy Prevention Programme.
- Offer high-dose folic acid—commonly 5 mg daily on prescription—before conception and through the first 12 weeks in line with the person’s UK preconception plan, while recognising it does not remove medicine-related risk.
- Pregnancy can increase clearance of medicines including lamotrigine and levetiracetam; a preconception baseline concentration and symptom-led serial levels can guide dose adjustment, followed by postpartum reduction when clearance normalises.
- Enzyme-inducing antiseizure medicines can reduce hormonal contraceptive effectiveness, while oestrogen-containing contraception can lower lamotrigine exposure; check a current interaction resource for every combination.
- NICE supports breastfeeding when desired after an individual medicine review, with observation of the infant and a plan for parental sleep and nocturnal seizure safety.
Key red flags
New seizures can follow falling drug concentrations, vomiting, missed doses, sleep deprivation or pregnancy-specific pathology and need prompt multidisciplinary assessment rather than automatic dose escalation.
A seizure after 20 weeks or postpartum, particularly with hypertension, headache, visual symptoms, epigastric pain or proteinuria, requires immediate obstetric treatment even in someone with established epilepsy.
Investigation priorities
Confirm the indication and identify a safer effective regimen before pregnancy begins.
Management branches
A person with epilepsy could become pregnant or is planning pregnancy.
- 1. Refer early to epilepsy specialists, confirm seizure and syndrome diagnosis, and review control, prior drug failures, current dose and reproductive safety.
- 2. If a safer effective regimen is available, complete cautious cross-titration and demonstrate stability before stopping contraception or attempting conception.
- 3. Prescribe high-dose folic acid according to current UK preconception advice and address smoking, alcohol, sleep, vaccinations and other medicines.
- 4. Agree baseline drug levels where useful, contraception during transition and who to contact immediately after a positive pregnancy test.
Key medicines
Folic acidUK practice commonly prescribes 5 mg orally once daily before conception and until 12 weeks of pregnancy for people taking antiseizure medicines; confirm timing and duration in the current specialist plan.Start before pregnancy where possible and do not delay epilepsy review. Confirm ongoing need after 12 weeks, check other supplements to avoid duplication and explain that adherence to antiseizure treatment remains important.
Lamotrigine in pregnancyContinue the individually effective divided dose; obtain a preconception reference when monitoring is planned and adjust in specialist care against seizures and concentration change rather than a universal target.Clearance commonly rises during pregnancy and returns rapidly postpartum, creating breakthrough then toxicity risks. Oestrogen contraception also lowers exposure; titration and rash precautions remain essential.