Antenatal Problems 2 Flashcards
What happens to BP during the first 24 weeks of pregnancy?
BP decreases early in pregnancy until 24 weeks due to decrease in systemic vascular resistance (due to progesterone)
What happens to BP in pregnancy after 24 weeks?
BP increases after 24 weeks until delivery due to an increase in stroke volume
What happens to BP after delivery?
BP decreases after pregnancy but may peak again 3-4 days post-partum (post-partum HTN)
What is PIH?
> 140/90mmhg in the second half of pregnancy in the absence of proteinuria or other markers of pre-eclampsia
What are those with PIH at an increased risk of developing?
Pre-eclampsia
- Increased risk with earlier onset of HTN
In post-partum HTN, what are symptoms such as epigastric pain, visual disturbances or new onset proteinuria indicative of?
Post-partum pre-eclampsia
What investigations should be done for PIH?
- Urinalysis = look for protein
- Bloods = FBC, U&Es, urate, LFTS, coagulation screen (normal if essential HTN in pregnancy)
- USS - foetal assessment
- Investigate underlying cause
What antihypertensives are safe in pregnancy?
First line:
- Labetalol
Second line:
- Nifedipine
Others:
- Methyldopa
A BP of what in pregnancy is a medical emergency?
> 160/110
If proteinuria develops = super-imposed pre-eclampsia
Which antihypertensives are contraindicated in pregnancy?
ACEi and ARBs = teratogenic
Beta blockers (except labetalol and oxprenolol) and calcium channel blockers (except nifedipine) should be avoided
Methyldopa:
- Dose
- SE
250mg BD up to 1g TDS
SE: depression - postnatally
Nifedipine:
- Dose
- SE
10mg BD up to 30mg TDS
SE: tachycardia, flushing, headache, peripheral oedema
Hydralazine:
- Dose
- SE
25mg TDS up to 75mg QDS
SE: tachycardia, pounding heartbeat, headache, diarrhoea
Labetalol
- Dose
- Avoid when?
100mg BD up to 600mg QDS
IV infusion for severe refractory HTN
Avoid in asthma
ACEi = given when?
Postpartum only as fetotoxic
Captopril safe in breastfeeding
What 3 criteria must be met to diagnose pre-eclampsia?
- Hypertension (>140/90) on 2 occasions at least 4 hours apart
- Significant proteinuria >300mg protein in a 24h urine sample OR >30mg/mmol PCR (urinary protein:creatinine)
- Greater than 20 weeks gestation
What is the pathophysiology of pre-eclampsia?
Mechanism poorly understood but the placenta plays a pivotal role
Suboptimal uteroplacental perfusion associated with a maternal inflammatory response and maternal vascular endothelial dysfunction. This leads to vascular hypermermeabiltiy, thrombophilia and HTN, which may compensate for reduced flow in uterine arteries.
Increased vascular resistance = HTN
Increased vascular permeability = proteinuria
Reduced placental blood flow = IUGR and reduced cerebral perfusion
How is mild/moderate/severe pre-eclampsia categorised?
Mild - BP 140/90 - 149/99
Moderate - BP 150/100 - 159/109
Severe - BP > 160/110 + proteinuria 0.5g/day
or
BP > 140/90 + proteinuria + symptoms
What are the moderate and the high risk factors for pre-eclampsia?
Moderate Risk Factors • Nulliparity • Extremes of maternal age • BMI >35 • Family history pre-eclampsia - mother or sister • Pregnancy interval > 10 years • Multiple pregnancy
High Risk Factors
• Chronic hypertension
• Previous hypertension, pre-eclampsia, eclampsia in previous pregnancy
• Pre-existing CKD
• Diabetes mellitus
• Autoimmune disease - SLE, antiphospholipid syndrome
What are the main symptoms of pre-eclampsia?
- Frontal headaches
- Visual disturbances - flashing lights
- Epigastric pain - hepatic capsule distension/infarction
- Sudden onset non-dependent oedema - puffy face
- Breathlessness - pulmonary oedema
- Nausea, vomiting
What are some maternal complications of pre-eclampsia?
- Eclampsia = tonic-clonic seizures resulting from cerebrovascular vasospasm
- Cerebral haemorrhage
- Liver / renal failure
- DIC
- Pulmonary oedema
- HELLP syndrome
- AKI
- Retinal detachment
What is HELLP syndrome and what is the characterised by?
A complication of pre-eclampsia
- Haemolysis
- Elevated Liver enzymes
- Low Platelet count
What are some fetal complications of pre-eclampsia? (5)
- IUGR
- Morbidity and mortality
- Placenta abruption
- Pre-term birth
- Hypoxia
What might an FBC show in pre-eclampsia?
- Thrombocytopenia - due to platelet aggregation on damaged endothelium, indicates impending HELLP or DIC
- Anaemia = if haemolysis
- Relative high Hb due to haemoconcentration
What would a clotting screen show in pre-eclampsia?
Prolonged PT and APTT
What would biochemistry investigations show in pre-eclampsia?
- Raised urate
- Raised urea and creatinine
- Abnormal LFTs - high AST and ALT
- Raised LDH = a marker for haemolysis
- Urinalysis = proteinuria
What is the cure of pre-eclampsia? When is it indicated?
Delivery of the placenta
Indicated if >34 weeks or <34 weeks with maternal/foetal instability
When is out-patient management of pre-eclampsia appropriate? What is the management plan?
- BP <160/110
- No or low (<0.3g / 24hrs) proteinuria
- Asymptomatic
- Pregnancy < 34 weeks
Management:
- Warn about the development of symptoms
- Review BP and urine every 1-2wks
- Weekly review of blood biochemistry
What is the management of mild-moderate pre-eclampsia, where BP <160 systolic and <110 diastolic with significant (2+) proteinuria and no maternal complications?
ie what should happen when significant proteinuria arises?
Admission advised:
- 4 hourly BP
- 24hr urine collection for protein
- Daily urinalysis
- Daily fetal assessment with CTG
- Regular blood tests (every 2-3 days unless symptoms/signs worsen)
- Regular USS = fortnightly growth and twice weekly doppler / liquor volume (depending on severity)
What is the management of pre-eclampsia where BP > 160/110?
Antihypertensives
First line - labetalol
Second line - nifedipine
Third line - methyldopa
Team involves senior obstetric, anaesthetic and midwifery staff
Aim to get to 34 weeks gestation (if need to deliver before 35 weeks, ensure IM steroids administered to aid foetal lung development)
What is the target BP in the management of pre-eclampsia?
140/90mmHg
What are some indications for immediate delivery in severe pre-eclampsia? (4)
- Worsening thrombocytopenia or coagulopathy
- Worsening liver or renal function
- Severe maternal symptoms esp epigastric pain
- Fetal reasons eg distress / reversed umbilical artery flow
- HELLP syndrome eclampsia
What is the usual method of delivery in severe pre-eclampsia?
Before 34wks = CS
After 34wks = IOL
What should be given to prevent seizures during delivery in a woman with pre-eclampsia?
IV magnesium sulphate - reduces risk of eclampsia by more than half
Consider epidural as this lowers BP
What is given to control seizures?
Magnesium sulfate
Loading dose of 4g given by infusion pump over 5-10mins, followed by a further infusion of 1g/hr maintained for 24hrs after the last seizure
What is eclampsia?
The occurrence of 1+ convulsions in a pre-eclamptic woman in the absence of any other neurological or metabolic causes
How is eclampsia managed?
Resuscitation:
- Pt put in left lateral position and airway secured
- 15L Oxygen via NRBM
Treatment and prophylaxis of seizures:
- Magnesium sulfate
- IV Lorazepam if unresponsive
Treatment of HTN:
- IV labetalol (both may precipitate fetal distress = continuous CTG)
Fluid therapy:
- Close monitoring of fluid intake and urine output
- Do not preload with colloid prior to regional anaesthesia
Urgent delivery
What can be given as prophylaxis of pre-eclampsia?
Low dose aspirin - 75mg OD from 12 weeks until birth
When does HELLP syndrome occur in pregnancy?
Usually rapid onset in second half of pregnancy
How does HELLP syndrome present?
Symptoms usually nonspecific
- 50% have headache
- 20% have visual symptoms
- Malaise, fatigue, RUQ / epigastric pain, n&v, flu-like symptoms
- Some have easy bruising / purpura
- On examination, oedema, HTN and proteinuria may be present
- Characterised by exacerbations of symptoms at night and relief during the day
- +/- hepatomegaly
What blood results would indicate HELLP syndrome?
- Haemolysis with fragmented RBC on film (due to microangiopathic) haemolytic anaemia
- Raised LDH >600 IU / L with a raised bilirubin (due to destruction of RBC)
- Liver enzymes are raised with AST or ALT level >70IU/L (due to liver injury)
- Decreased platelets due to activation and increased consumption
What is the treatment of HELLP?
- IV fluids
- Blood transfusions
- Antihypertensive agents
- Magnesium sulphate
- Delivery if >34 weeks or <34 weeks if maternal/foetus compromise
What are the signs found on examination in pre-eclampsia?
- Hypertension
- Proteinuria, oliguria
- Hyper-reflexia, clonus
- Pulmonary oedema