Epilepsy in Pregnancy Flashcards
How does seizure frequency change during pregnancy?
Seizure frequency most commonly stay the same however, for some it increases or decreases.
Do seizures effect the foetus?
Foetus can tolerate seizures but there is an increased risk of foetal demise with status epilepticus.
Whats the biggest problem with epilepsy and pregnancy?
Most anticonvulsants are teratogenic to some extent. If taking multiple drugs, then there is an increased risk of congenital abnormalities. Even if not on therapy there is a still an increased risk of congenital abnormalities. Changes to medication should only take place prior to conception. Once pregnant the teratogenic risk has already occurred.
1-2% of new-borns will have congenital defects with non-epileptic mother. This rises to 3-4% in patients who take antiepileptics.
What should be given women prophylactically to try and reduce the teratogenic risk?
Folate 5mg should be given to reduce the risk of some abnormalities.
How do antiepileptic and contraceptives interact with each other?
Must be careful with contraception as many epileptic medications are enzymes inducers/inhibitors so progesterone only is inadequate. Also, oestrogen-based contraceptive may lower lamotrigine levels.
Other than congenital abnormalities what other risks do anticonvulsant therapies post?
Teratogenicity
Neonatal withdrawal
Vitamin K deficiency – enzyme inducers so haemorrhagic disease of the new-born
Developmental delay and behavioural problems
Which antiepileptic medications are enzyme inducers and which aren’t
Enzyme-inducing anticonvulsants Carbamazepine * Phenobarbital Phenytoin Primidone
Non-enzyme inducing anticonvulsants Valproate * Lamotrigine Gabapentin Ethosuximide
Which anticonvulsants are best in pregnancy?
Carbamazepine considered the least teratogenic
Lamotrigine low rate of congenital malformations
Sodium Valporate – neural tube defects
Phenytoin – cleft palate
What differentials should be considered in a first seizure presentation in pregnancy?
Eclampsia, epilepsy, infection (meningitis, encephalitis or abscess), metabolic (drug or alcohol withdrawal, drug toxicity, hypoglycaemia, electrolyte imbalance), hypoxia, space occupying lesion and vascular (stroke, TTP (thrombotic thrombocytopenic purpura) or cerebral vein thrombosis).
How should a first seizure in pregnancy presentation be investigated?
All women with a first seizure in pregnancy should have a CT head or preferably an MRI.
As well as BP and protein measurements
How should epilepsy be managed before pregnancy occurs?
Reduce drugs to the minimal number and dose that controls seizures
Consider stopping if seizure free for > 2yrs
Folate 5mg for at least 12 weeks preconception (all epileptic women of child bearing age should take folate)
How should epileptic mothers be cared for antenatally?
Do NOT change medication if well controlled
Stress important of compliance
Prenatal screening – alpha fetoprotein and detailed anomaly scan
Consider vitamin K for last 4 weeks
Showers rather than baths and avoid sleep deprivation
How should epileptic mothers be managed during labour and delivery?
Vaginal delivery – seizure not an indication for CS unless status epilepticus
Note labour often increases risk of seizure
Control seizures with benzodiazepines
How should epilpetic mothers be cared for postnatally?
Neonatal vitamin K to reduce risk of haemorrhagic disease of the new-born
Breast feeding is fine although may cause slow withdrawal or sedation if benzos
Return anticonvulsant back to normal
Contraception – COCP 50ug oestrogen with shorter pill free interval, IUCD ideal, mini pill less effective.
General care to minimise risk to baby if a seizure occurs
