Pregnancy: Effects on pre-existing conditions Flashcards
Incl Asthma Epilepsy DM cardiac disease
Recap: pathophysiology of asthma?
- Reversible bronchoconstriction of airways from smooth muscle spasm.
- Damage airway epithelial cells - get shedding, subepithelial fibrosis, and basement membrane thickening.
- Inflammatory reaction characterised by eosinophils, Th2 cells and mast cells. Inflammatory mediators released include histamine, leukotrines and prostaglandins.
- Increased mucus production due to increased number of mucus secreting goblet cells.
Symptoms of asthma?
Cough
Breathlessness
Wheeze
Chest tightness
Diurnal variation
Hx of atopy - eczema and hayfever
Differentials for pt presenting with wheeze?
Acute asthma exacerbation
Bronchitis - viral or bacterial
PE
GORD
Allergy
Hyperventilation/ Psychosocial
How is asthma diagnosed in pregnancy?
Based on Hx
>20% diurnal variation in PEFR for 3+ days
>15% improvment in FEV1 after inhaled bronchodilators.
How can pre-existing asthma be affected in pregnancy?
May remain unchanged
If poorly controlled before pregnancy, asthma may worsen
How can asthma affect fetus?
Can result in fetal growth restriction
Can result in preterm labour
Management of asthma in pregnancy?
- Focus on preventing acute attacks
- follow BTS guideline (picture)
- Most meds are safe in preg –> do NOT start leukotriene receptor antagonist
- Continue usual medication and treat as for non-pregnant patient
- Check inhaler technique
- Smoking cessation advice
Why are asthma attacks in pregnancy rare?
Due to endogenous steriod production
Triggers for asthma exacerbation?
Pollen
Animal fur
Dust
Exercise
Cold
Emotion
URTI
Medications - aspirin (preeclampsia), beta blockers
Carboprost is given in PPH. How would you go about using this in an asthmatic mother?
With caution - as it can cause bronchospasm
Differentials/Causes of seizures in pregnancy?
Epilepsy
Eclampsia
Cerebral vein thrombosis
Intracranial mass
Stroke
Hypogylcaemia
Hyponatraemia
Drugs and withdrawal
Infection
How would you manage epilepsy preconception?
- Involve neurologist to confirm Dx
- Optimise treatment - aim for seizure control on lowest dose to minimize risk of congenital malformation. Can consider withdrawing if seizure free for 2yrs.
- Folic acid 5mg daily needs to be taken >3months preconception
- Discuss increased risk of epilepsy in children (4-5% if just mother affects, 20% if both parents affected)
Discuss AEDs and congenital malformations (CMs):
* which AEDs can lead to CMs?
* What CMs can they cause?
Which AEDs?
* Sodium valproate, carbamazepine = should not be prescribed if child bearing age.
Valproate: highest rate of CMs –> NTDs, craniofacial abnormalities, neurodevelopmental problems
Carbamazepine: increased rates of NTDs
Lamotrigine: malformation rate of 2.1%. Need bloods checked regularly. Avoid in breastfeeding.
How would you manage a pregant lady with epilepsy in antenatal care?
- needs to attend a consultant led obstetric clinic
- aim for vaginal delivery
- do not change epilepsy drugs without advice from epilepsy specialist
- if unplanned preg - need to see epilepsy specialist ASAP to talk through AEDs
- needs to have nuchal translucency and anomaly scans, as well as serial growth scans in 3rd trimester (risk of SGA fetus)
- discuss that sleep deprivation and stress can increase seizure risk - so avoid wherever possible (esp in labour)
What intrapartum care would you discuss with pregnant lady with epilepsy?
- Aim for vaginal delivery unless obstetric indications require C section.
- Having a fit in labour is not an indication for C section unless it is status epilepticus.
- delivery should be in hospital and AEDs should be continued in labour
- pain relief is priority - epidural is safe
- use benzos if seizure not self terminating = lorazepam 4mg IV, diazepam 10-20mg IV.
- Seizures are more common intrapartum and postpartum due to sleep deprivation and reduced drug absoroption
What postnatal care would you put in place for new mother with epilepsy?
- Baby needs 1mg vit K (for haemorrhagic disease of newborn)
- avoid early discharge - needs to be in hosp for 24hrs
- discuss strategies for avoiding dropping baby during seizure (eg change baby on floor)
- encourage breastfeeding
- review AED dose within 10 days of delivery to avoid toxicity
A lady with known epilepsy has just given birth. She wants to discuss contraception. What would you inform her?
If she takes enzyme inducing AEDs - use copper/mirena coil and injected progestogens
If on non-enzyme inducing AEDs, can take any contraception
Oestrogen containing contraception increases seizure risk if she is taking lamotrigine due to reduced drug levels.
Define HTN in pregnancy
systolic > 140 mmHg or diastolic > 90 mmHg
or
an increase above booking readings of > 30 mmHg systolic or > 15 mmHg diastolic
Define HTN in pregnancy
systolic > 140 mmHg or diastolic > 90 mmHg
or
an increase above booking readings of > 30 mmHg systolic or > 15 mmHg diastolic
Describe clinical features of pre-existing HTN in pregnancy
A history of hypertension before pregnancy or an elevated blood pressure > 140/90 mmHg before 20 weeks gestation
No proteinuria, no oedema
More common in older women
Describe clinical features of pregnancy induced hypertension (aka gestational HTN)
HTN occuring in the second half of pregnancy (after 20wks)
No proteinuria, no odema
Resolves following birth (usually after 1 month)
What are women with pregnancy induced (gestational) HTN at increased risk of?
Future pre-eclampsia
HTN in later life
Desrcribe clinical features of pre-eclampsia, and compare this to pregnancy induced (gestational) HTN
Pre-eclampsia: Preg-induced HTN in association with proteinuria (>0.3g/24hrs)
Odema may occur.
After 20weeks
PIH: HTN occuring in second half of pregnancy. No proteinuria and no odema.
A pregnant woman has pre-existing HTN and is on ramipril, an ACEi. How should you manage this?
Stop ACEi or ARB immediately.
Alternative antihypertensive (labetalol) should be started whilst awaiting a specialist review
What are the different classifications of hypertensive disorders in pregnancy?
Gestational / Pregnancy induced HTN
Pre existing HTN / Chronic HTN
Pre-eclampsia
Pre-eclampsia superimposed on chronic HTN
Eclampsia
Describe trend in BP in pregnancy
In early pregnancy to 24 weeks, BP falls due to fall in vascular resistance
After this time, stroke volume increases, leading to a rise in BP.
What BP in pregnancy is considered a medical emergency?
BP of >160/110 mmHg
Women with chronic HTN have higher risks of….WHAT?
- pre-eclampsia
- fetal growth restriction
- placental abruption
How would you pharmacologically manage women at high risk of developing pre-eclampsia?
Aspirin 75mg OD from 12weeks - birth of baby
Management of HTN in pregnancy?
Management
* oral labetalol is now first-line following the 2010 NICE guidelines
* oral nifedipine (e.g. if asthmatic) and hydralazine
A woman presents for the first time with HTN in pregnany. What other causes of HTN should you rule out?
Coarctation
Renal artery stenosis
Other renal disease
Rare: Conn syndrome, Cushing syndrome, phaeochromocytoma
A woman has HTN in pregnancy. What antenatal care should you have in place from 28weeks and why?
Fetal US every 4 weeks from 28/40 to assess:
- fetal growth
- amniotic fluid volume
umbilical artery doppler
Oxytocin may be given in third stage of labour to prevent PPH. Why is ergometrine NOT given for this in a woman with HTN?
ergometrine causes severe HTN - which is a huge RF for stroke.
Maternal risks of DM in pregnancy?
Fetal risks of DM in pregnancy?
Maternal:
Hypoglycaemia unawareness
Increased risk of pre-eclampsia
Increased risk of infection
Higher rates of C section
Fetal:
Miscarriage
Congenital malformation rates increase (but reduced by good glycaemic control)
Macrosomia –> shoulder dystocia
Growth restricted fetus
Polyhydraminos
Pre-term labour
Stillbirth
What pre-conception counselling would you discuss for women with pre-existing DM?
- avoid unplanned pregnancy
- Use contraception until good blood glucose has been achieved < 48mmol/mol
- folic acid 5mg daily until 12 weeks gestation
- BMI < 27
- Stop oral hypoglycaemics (apart from metformin), statins, ACEi
- Treat retinopathy pre-pregnancy
What antenatal care would you discuss with woman who has pre-existing DM?
- Need joint clinic with diabetologist, diabetes specialist nurse, obstetrician, midwife
- folic acid 5mg from preconception
- aspirin 75mg OD from 1st trimester to reduce risk of HTN and pre-eclampsia
- meaure HbA1c at booking
- Discuss use of insulin
- Educate about benefits of normal blood sugar levels
- Discuss hypoglycaemia awareness
- Give glucogel and glucagon kit
- Early USS at 7-9 weeks to confirm gestation. Offer combined screening at 12wks, detailed anomaly scan 18-20weeks and growth scans from 28-36weeks
When is delivery recommended for women with pre-existing DM?
In hospital
At 37-38 +6 weeks
C section discussion required if fetus is macrosomic
If preterm - corticosteriods should be given to promote fetal lung maturity
A pregnant woman who has a PMH of VTE is attending your clinic.
1. Is she low risk or high risk?
2. What management does she need?
- high risk
- needs LMWH throughout antenatal period - the dose depends on body weight
Assessment at booking should include RFs that increase a woman’s likelihood of developing a VTE. What are these RFs?
- Age > 35
- Body mass index > 30
- Parity > 3
- Smoker
- Gross varicose veins
- Current pre-eclampsia
- Immobility
- Family history of unprovoked VTE
- Low risk thrombophilia
- Multiple pregnancy
- IVF pregnancy
- Previous VTE
At booking, an assessment of RF for VTE is done. How many RFs warrant immediate treatment with LMWH?
4 + RF = immediate treatment
3 RF - LMWH should be started at 28weeks and continued until 6weeks postpartum.
For VTE, what treatments are avoided in pregnancy?
DOACs
Warfarin
What are RFs for having VTE during pregnancy?
If you…
* are admitted to hospital
* are carrying more than one baby (multiple pregnancy)
* become dehydrated or less mobile in pregnancy due to, for example, vomiting in early pregnancy, being in hospital with a severe infection such as appendicitis or a kidney infection or if you are unwell from fertility treatment (ovarian hyperstimulation syndrome)
* are immobile for long periods of time, for example after an operation or when travelling for 4 hours or longer (by air, car or train)
* have pre-eclampsia
RF for VTE following birth?
If you..
* have a very long labour (more than 24 hours)
* have had a caesarean section
* lose a lot of blood after you have had your baby
* receive a blood transfusion
Investigations for PE?
- a chest X-ray (after birth)– this can also identify common problems that could be the cause of your symptoms, such as a chest infection
- a CT scan (specialised X-ray) of your lungs
- a VQ scan (ventilation/perfusion scan) of your lungs – this involves a drip into a vein in your arm
- an ultrasound scan of both your legs if you have any symptoms of a DVT.
How can a woman reduce her risk of getting a DVT/PE when pregnant/after birth?
(conservative management)
- stay as active as you can
- wear special stockings (graduated elastic compression stockings) to help prevent blood clots
- keep hydrated by drinking normal amounts of fluids
- stop smoking
- lose weight before pregnancy if you are overweight
Why is LMWH safe to give to pregnant lady?
It does not cross the placenta, so does not pose any harm to the baby
What is the risk of using nifedipine during pregnancy?
Nifedipine may cause a sudden, severe drop in blood pressure and compromise the uteroplacental circulation and in turn the foetus
Management of pre-exisiting DM in pregancy?
- weight loss for women with BMI of > 27 kg/m^2
- stop oral hypoglycaemic agents, apart from metformin, and commence insulin
- folic acid 5 mg/day from pre-conception to 12 weeks gestation
- detailed anomaly scan at 20 weeks including four-chamber view of the heart and outflow tracts
- tight glycaemic control reduces complication rates
- treat retinopathy as can worsen during pregnancy
