Medical Disorders in Pregnancy

Question 1

What is the criteria for pre-eclampsia?

Answer 1

• New onset hypertension AND
  
  • Protinuria OR
  • End organ dysfunction OR
  • Fetoplacental insufficiency

Question 2

What is the pathophys of pre-eclampia / eclampsia?

Answer 2

• Early onset disease <34w
  
  • ​Stage 1 1st trimeseter
    
    • Abnormal placentation
    • Failed remodelling of spiral arteries into high capacitance low resistance vessels leading to impaired placental perfusion
  • Stage 2
    
    • ​Increased proinflamatory cytokines and antiangiogenic factors leading to maternal endothelium dysfunction
• Late onset disease >34 weeks
  
  • ​Subclinical endothelial dysfunction (comorbidities) leadint to smaller threshold to tip towards widespread endothelial dysfunction

Question 3

What are the risk factors for pre-eclampsia/eclampsia?

Answer 3

• High risk if one is present
  
  • ​HTN disease in previous pregnancy
  • CKD
  • Chronic HTN
  • T1/T2 DM
  • Systemic autoimmune disease (SLE, antiphospholipid syndrome)
• High risk if two are present
  
  • ​1st pregnancy or multiple pregnancies
  • >40
  • BMI>35 at first visit
  • Phx of pre-eclampsia (mother / sister)
  • Inter-pregnancy interval >10y

Question 4

What is the range of protinuria for pre-ecclampsia?

Answer 4

>300mg per 24h urine collection of protine:creatinine ratio >0.3

Question 5

What are the markers for end organ dysfunction in pre-eclampsia?

Answer 5

• Haem: Thrombocytopenia <100,000
• Hepatic: increased AST/ALT >40, RUQ pain
• Pulmonary: Pulmonary embolism
• Neuro: Convulsions, hyperreflexia with sustained clonus, persistent new headache, persistent visual disturbance, posterior reversible encephalopathy syndrome, retinal vasospasm, stroke
• Uteroplacental: FGR, Abnormal umbilical artery dopler, stillbirth

Question 6

What are the history buzzwords for pre-eclampsia?

Answer 6

• Severe headache
• Visual disturbance
• Epigastric or RUQ pain
• Facial swelling
• Extremity swelling

Question 7

What is the relevant exam for a patient with pre-eclampsia?

Answer 7

• Vitals + BP
  
  • 140 - mild
  • 150 - mod
  • 160 - severe
• Abdo
  
  • Lie
  • Presentation
  • Size
  • RUQ pain / tenderness
• Neuro
  
  • Reflexes
  • Clonus
• Periphery
  
  • Oedema

Question 8

What are the necessary investigations for pre-eclampsia?

Answer 8

• Bedside
  
  • Urinalysis
  • CTG
  • Urine output
• Bloods
  
  • Pre-eclampsia screen (weekly)
    
    • UEC
    • LFT
    • FBC
    • Uric acid
    • Coags (if low platelets, lft abnormal, or reduced HB)
• Imaging
  
  • Fetal biometry
  • Doplers (umbilical, middle cerebral, ductus venosum)

Question 9

What is the prophylactic treatment for pre-eclampsia in high risk pregnancies?

Answer 9

Low dose aspirin (150mg) starting before 16w and continuing until 36w

Question 10

What is the antenatal management of preeclampsia

Answer 10

• Admission if HTN SBP>160 DBP>110 or concernic bloods
• Weekly checkups and monitoring
• Antihypertensives gradual reduction to 130-140/80-90
• Antenatal corticosteroids at 24-36w+6 for women at risk of preterm birth
• Magnesium sulfate for eclampsia prohpylaxis and neuroprotection
• Planned early birth if >37W +uncontrolled HTN, severe PET, neuro cx, APO, placental abruption, non-reassuring foetal status
• Expectant management for <34W: steroids +magnesium sulfate
• Prompt birth by CS is eclamptic seizure, sever pre-eclampsia

Question 11

What is the intrapartum management for pre-eclampsia?

Answer 11

• regional anaesthesia lowers BP
• Intrapartup blood tests
• Withold ergometrine
• Oxytocin IM or slow IV bolus

Question 12

What is the immediate management for severe HTN in pre-eclampsis?

Answer 12

• Two large IV bore cannulas and IDC
• IV fluid bolus
• Oral nifedipine or IV Labetolol or hydralazine
• Continuous CTG until normal +BP control
• 30minute maternal obs

Question 13

What antihypertensives are used in pre-eclampsia?

Answer 13

• Methyl dopa (slow onset- caution in depression, avoid post-partum)
• Labetolol (caution in asthma)
• Nifedipine XR (can cause severe headache and peripheral oedema)
• Hydralazine (for resistant HTN)

Question 14

What is the post-partum management for pre-eclampsia?

Answer 14

• Continue magnesium sulfate for 24 with strict fluid balance until good diaresis
• Discharge and community followup if BP<150/100
• Antihypertensives- target is <140/90
• Councelling for CV risks

Question 15

What are the four aspects for the treatment of eclampsia (pre-eclampsia + seizure)?

Answer 15

1. Resuscitation
   
   • recovery position
   • Code pink + anaesthetist
   • Magnesium sulfate
   • Diazepam or clozepam IV if seizure is prolonged
   • IV access and vitals
2. Seizure prevention
   
   • 25g magnesium sulfate (4g loading dose, 1g/h)
   • 2g/10min over each episode
3. Control HTN
4. Monitoring and investigations
   
   • Magnesium sulfate toxicity
   • CTG

Question 16

What are the contraindications of magnesium sulfate?

Answer 16

• Maternal myasthenia gravis
• Heart block
• Myocardial damage
• Caution in
  
  • renal insufficiency
  • CCB (nifedipine coadministration)

Question 17

What are the signs of magnesium sulfate toxicity?

Answer 17

• Loss of deep tendon reflexes
• RR 4 below baseline of <12 per minute
• Falling SaO2
• Nausea / vomiting
• Slurred speech / weakness / sleepiness
• Double vision
• Diastolic BP decrease 15mmHg
• Urine output <100ml over 4h
• Respiratory or cardiac arrest

Question 18

What is the treatment for magnesium sulfate toxicity?

Answer 18

Cease magnesium sulfate + administer calcium gluconate and monitor with ECG

Question 19

What is the therapeutic range for magnesium sulfate?

Answer 19

1.7-3.5 mmol/L

Question 20

What differentiates chronic HTN in pregnancy from pre-eclamspia?

Answer 20

• Pre-existing
• No protinuria or end organ dysfunction

Question 21

What differentiates Gestational HTN from pre-eclampsia and chronic HTN?

Answer 21

• No protinuria
• New onset
• Normalises 12W post-partum