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Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.

Epilepsy and antiseizure medicines

Obstetrics and gynaecology · UK scope · Sources checked 7 Sept 2026 · Clinical review pending

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A prolonged convulsion requires immediate treatment

A convulsive seizure lasting five minutes or recurrent seizures without recovery is status epilepticus; a new seizure after 20 weeks or postpartum may instead be eclampsia.

Action: Call emergency medical and obstetric help, protect airway and circulation, check glucose and give rescue treatment according to the seizure plan. Assess urgently for eclampsia and other causes, using magnesium sulfate when eclampsia is suspected rather than assuming known epilepsy explains every event.

Synopsis

Maintain seizure control while reducing reproductive medicine risk, recognise changing antiseizure-drug exposure during pregnancy, and plan emergency, intrapartum and postnatal care.

  • Do not stop antiseizure medication abruptly when pregnancy is discovered; arrange urgent individual review of seizure and fetal risks.
  • Optimise treatment before conception where possible, favouring an effective lower-risk single drug at the lowest dose that maintains control.
  • Lamotrigine and levetiracetam have comparatively reassuring pregnancy data, but suitability depends on seizure type, prior response and individual adverse effects.
  • Prescribe folic acid 5 mg orally daily before conception through 12 weeks for patients taking relevant antiseizure medicines.
  • Valproate has major reproductive risks and strict MHRA restrictions, including two-specialist agreement for new initiation below age 55 and Pregnancy Prevention Programme requirements where applicable.
  • Topiramate is contraindicated for migraine prevention in pregnancy and for epilepsy in pregnancy unless no suitable alternative exists; a Pregnancy Prevention Programme applies to those who could become pregnant.
  • Obtain a useful preconception drug-level baseline when monitoring is indicated, and act on clinical and concentration changes during pregnancy.
  • If doses increased during pregnancy, plan reduction towards preconception doses in the first days after birth with monitoring for toxicity and breakthrough seizures.

Key red flags

A seizure lasting at least five minutes, repeated convulsions without recovery or persistent reduced consciousness requires emergency resuscitation and hospital treatment.

New headache, visual disturbance, hypertension or epigastric pain accompanying a seizure raises concern for eclampsia even with a prior epilepsy diagnosis.

Pregnancy while taking valproate or topiramate requires urgent specialist review, but abrupt self-discontinuation can precipitate dangerous seizures.

Increasing seizures, inability to retain medication or a sudden fall in a relevant drug concentration requires prompt epilepsy-team assessment.

Investigation priorities

01
Detailed seizure and treatment historyFirst step

Define control, syndrome, adherence and exposure before changing medication.

Management branches

Preconception planningAgree a stable effective regimen

A patient with epilepsy is considering pregnancy or needs reproductive counselling.

  1. Review seizure syndrome, recent control, prior medicine trials and reproductive preferences with an epilepsy specialist.
  2. Optimise an effective regimen before conception where feasible and document folic acid, contraception and applicable MHRA safeguards.
  3. Obtain relevant baseline levels and provide written instructions for a positive pregnancy test, missed doses and prolonged seizures.

Key medicines

Folic acid with antiseizure treatmentPrescribe 5 mg orally once daily before conception and continue until 12 completed weeks of pregnancy, ideally starting several months before trying to conceive.Folic acid does not eliminate drug-related congenital or neurodevelopmental risk and must accompany, rather than replace, medication review.
Levetiracetam for an appropriate epilepsy syndromeThe cited adult SmPC therapeutic starting dose is 500 mg orally twice daily, with lower initial dosing possible for tolerability and specialist titration up to 1,500 mg twice daily; an established pregnancy regimen is adjusted to clinical control and the individual monitoring plan.Adjust for renal impairment, assess mood or behavioural adverse effects and monitor pregnancy-related concentration changes; never substitute it abruptly for another established antiseizure medicine.
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Sources and review status7 sources · checked 7 Sept 2026 · clinical review pending+
Sources

Sources and review status

National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 7 Sept 2026; clinical approval remains outstanding.

  • NICE NG217: Treatment safety and pregnancy monitoring
  • NICE NG217: Status epilepticus and prolonged seizures
  • MHRA: Valproate reproductive risks and current requirements
  • MHRA: Topiramate Pregnancy Prevention Programme
  • MHRA: Antiseizure medicines pregnancy safety review
  • Levetiracetam 500 mg tablets: current SmPC
  • Lorazepam Macure injection: SmPC

Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem · Content changes

Authoring stateRapid draftClinical stateAwaiting reviewJurisdictionUnited Kingdom