Chapter 5 - Medical disorders in pregnancy Flashcards
“will my epilepsy get worse during pregnancy?”
37% of womens seizures increase
13% decrease
50% remain the same
**those who’s epilepsy is poorly controlled are at highest risk of increasing seizure frequency
“Will my seizures affect my baby?”
- Usually fetuses tolerate seizures without complications, but status epilepticus increases the risk of demise
- However, women with epilepsy have an increased risk of congenital anomalies (mostly due to meds, especially polypharmacy but even in women off meds. Higher dose = increased risk. Dividing doses may reduce peak = reduce risk.
- Change before becoming pregnant, once pregnant don’t change doses as risk has already occured + increase risk of poor control.
- Taking folic acid can help to minimize risks
What are the risks of anticonvulsants during pregnancy?
• Teratogenicity: congenital anomalies or fetal anticonvulsant
syndrome.
• Neonatal withdrawal.
• Vitamin K deficiency (enzyme inducers) –> haemorrhagic disease of
newborn.
• Developmental delay and behavioural problems.
Differentials for a woman with her first seizure in pregnancy
• Eclampsia. • Epilepsy. • Infection: - meningitis - encephalitis - abscess. • Metabolic: - drug or alcohol withdrawal - drug toxicity - hypoglycaemia - electrolyte imbalance (raised Na/ca, decreased Na). • Severe hypoxia. • Space-occupying lesion. • Vascular: - cerebral vein thrombosis - thrombotic thrombocytopaenic purpura (TTP) - cerebral infarction or haemorrhage.
Inx for a woman with her first seizure in pregnancy
- CT or MRI (preferable) + Neuro review
Risks of valproate to fetus
- Neural tube defects: increase 10-fold (1–2%).
- Genitourinary anomalies (hypospadias).
- Cardiac anomalies.
- Facial clefts.
- Neurodevelopmental delay: increase 3.5-fold.
Risks of carbamazepine to fetus
- Neural tube defects (0.5–1%).
- Cardiac anomalies.
- Facial clefts.
Risks of phenytoin to fetus
- Facial clefts: i 5-fold.
* Cardiac anomalies.
Pre-pregnancy management of epilepsy
1) confirm epilepsy
2) Educate
3) use least amount of meds
4) Consider stopping if seizure free for 2years
5) 5mg folic acid for 12weeks before conception + continue until delivery
6) 4% risk of child with epilepsy if one parent affected, 15% if both affected
Antenatal management of epilepsy
1) Don’t change meds
2) Prenatal screening (a-fetoprotein for neural defects + anomaly scan for clefts and cardiac abnormalities)
3) Fetal echo at 22 weeks
4) Vit K 10mg/day for last 4 weeks of pregnancy (neonatal coagulopathy)
5) General advice - showers not bathes ect. good amount of sleep
6) some women have to go up on meds
labour in epileptics
- Aim vaginal
- Labour increases risk of seizures
- control seizures with benzos
Post-natal care for epileptics
• Neonatal vitamin K to lower risk of haemorrhagic disease of the newborn.
• Breast-feeding is not contraindicated (anti-convulsants reach breast milk and thus slow withdrawal occurs, although phenobarbital and benzodiazepines may cause sedation in the baby).
• If the anticonvulsant dose was increased reduce it back slowly
• Contraception with enzyme-inducing drugs:
- COCP containing 50 micrograms oestrogen with a shorter pill-free interval
- progestogen-only pill (POP) is less effective
- intrauterine contraceptive device (IUCD) is ideal.
• General advice (bathing and feeding) to minimize risk of harm to baby from seizures.
When during pregnancy is there an increased risk of CVA?
Post-partum - There is a 9-fold increased risk for infarcts and 28-fold increase for haemorrhagic stroke in the first 6wks postpartum
compared with non-pregnant women.
Symptoms of CVA
- Abrupt onset of weakness.
- Sensory loss.
- Dysphasia.
RF for CVA
- Smoking.
- Diabetes.
- Hypertension.
- Hypercholesterolaemia.
The most common cause of SAH outside pregnancy
Ruptured berry aneurysm,
but arteriovenous malformations (AVMs) may dilate in pregnancy due to
the effect of oestrogen, resulting in a similar incidence
Presentation of SAH
- Headache.
- Vomiting.
- Loss of or impaired consciousness.
- Neck stiffness.
- Focal neurological signs.
Mx of SAH
• Early treatment = reduce the chance of subsequent
bleeding (the risk is high for AVM).
• Surgery; excision of the AVM, coiling, or clipping.
• Interventional radiology is associated with exposure of the fetus to large doses of radiation.
• Nimodipine to decrease vasospasm.
• Delivery:
- labour is high-risk for bleeding, recommend elective CS if the lesion is inoperable
• epidural anaesthesia is contraindicated with a recent subarachnoid haemorrhage (SAH) due to raised intracranial pressure
• if the lesion has been successfully treated = vaginal delivery (a longer passive 2nd stage with early use of assisted delivery may reduce the risk of rebleeding).
Causes of CVAs in pregnancy
Infarcts • Pre-eclampsia/eclampsia. • Central nervous system (CNS) vasculitis. • Carotid artery dissection. • Emboli: - itral stenosis - peripartum cardiomyopathy - endocarditis - paradoxical emboli. • Coagulopathies: - Thrombophilia - Antiphospholipid syndrome. -Thrombotic thrombocytopaenic purpura. - Cerebral vein thrombosis.
Haemorrhagic • Pre-eclampsia/eclampsia. • DIC. • AVM. • Ruptured berry aneurysm. • CNS vasculitis.
Inx of CVA
**Liaise with neuro • M RI or CT scan of head. • Cerebral angiography +/– venography. • Echocardiogram. • Carotid Dopplers. • Thrombophilia screen and antiphospholipid antibodies. • Homocystine level/methylenetetrahydrofolate reductase (MTHFR) screen .
Antenatal mx of cardiac disease
1) MDT mx
2) Optimize CV stability - ?surgery, optimize meds
3) Educate on risks
4) Estimate CV tolerability - NYHA exercise tolerance, pulmonary Ht or cyanosis
5) Consider if termination is necessary
6) Correct factors that may cause decompensation - anaemia, infection, Htn or arrhythmia
7) Monitor with maternal echos and fetal growth US (IUGR or death in utero especially with cyanosis)
Should all women with CV disease have a CS?
- Aim for vaginal delivery with a short 2nd stage unless; aortic root >4.5cm, LVEF <30%, aortic dissection or aneurysm
Key points in mx of women CV during labour
1) Have a clear pre-set plan
2) Consider whether CS or vaginal delivery is necessary
3) Aim for a short second phase
4) Monitoring throughout
5) Minimize blood loss by active mx of 3rd stage + oxytocin infusion (avoid ergometrine and prostaglandins)
6) Epidurals may help CV stability (controlling HR + BP due to pain)
7) Strict fluid mx
Describe 5 normal haemodynamic changes in normal pregnancy
1) Peripheral vasodilation –> lowers BP
2) CO increases during pregnancy and further during labour
3) CO increases further following delivery due to increased venous return
4) Colloid osmotic pressure falls –> increased risk of pulmonary oedema
5) Hypercoagulability
Does CO increase or decrease after delivery?
CO increases following delivery due to increased venous return:
• relief of vena caval obstruction
• tonic uterine contraction (expels blood into systemic circulation).
Which groups of women with CV disease are considered as high risk aka 50% mortality?
- Pulmonary hypertension.
- Aortic dissection.
- Complicated aortic coarctation.
- Marfan’s syndrome with significant aortic root involvement.
- Myocardial infarction.
Moderate risk
• Mitral stenosis NYHA class 3 or 4.
• Severe aortic stenosis.
• Mechanical heart valves.
Risk of artifical heart valves in pregnancy
- Women have near normal cardiac function
- Risk is due to anti-coagulants
- But they must be continued due to risk of stoke and valve thrombosis
Benefits and risks of LMWH
- Less maternal bleeding
- No risk to fetus as it doesn’t cross the placenta
- Increased risk of embolic events, valve thrombosis, osteoporosis and heparin induced thrombocyopenia than warfarin
= safer for the baby, less safe for the mum
Benefits and risks of warfarin
- Increased risk of miscarriage, warfarin embryopathy, maternal and neonatal bleeding
- long half life
- Lower risk of embolic events and valve thrombosis than LMWH
By what time should all women on warfarin be switched to LMWH?
37weeks
When should LMWH be stopped and restarted?
stopped in labour, restarted after delivery
