Clinical consequences of poor placentation Flashcards
Why is it important to learn about pre-eclampsia
6th leading cause of direct maternal deaths (6 deaths over 3 years) • Commonest medical problem in pregnancy: – Gestational hypertension = 10% – PE = 2-5% – Severe PE= 1% – Eclampsia at a 2% death rate • Leading cause of iatrogenic prematurity • Immediate risks of eclampsia, stroke and heart failure • Life-long risk of cardiovascular disease
What are some high and moderate risk factors of pre-eclampsia
high risk factors: Previous pre-eclampsia Chronic hypertension Autoimmune disease Diabetes mellitus Chronic kidney disease
Moderate risk factors Nulliparity Age >40 Pregnancy interval >10yr BMI >35 Family hx pre-eclampsia Multifetal gestation
Describe the pathophysiology of pre-eclampsia
Defective spiral artery remodelling
Causes placental hypoperfusion
diseased placenta releases pro-inflammatory proteins into maternal circulation
diseased placenta releases pro-inflammatory proteins into maternal circulation
this causes systemic vasoconstriction and endothelial dysfunction
causes hypertension and end organ damage
Remember HELLP Hameolysis Elevated Liver enzymes Low Platelets
Placentation in normal vs pre-eclampsia
Normal: • Normal • Trophoblasts invade maternal vessels • Narrow spiral arteries remodelled • Wide-bore low-resistance vessels deliver large amounts of maternal blood • Nutrient and oxygen delivery to foetus
PE:
Deficient trophoblast invasion • Spiral arteries not remodelled • High-resistance placental bed • Poorly perfused hypoxic placenta • Deficient nutrient and oxygen delivery • Release of inflammatory cytokines (IL, TNF etc) • Maternal endothelial dysfunction: – Increased vascular reactivity and vasospasm – Increased capillary permeability and reduced intravascular volume
Describe the cardiovascular placental axis
Feto placental demands can sometimes be under excessive demand
These can include foetal macrosomia, twin pregnancies, prolonged pregnancy excess weight gain
This can have a negative impact on cardiovascular health causing cereobrovascular/cardiovascular morbidity or CKD
In the foetus some factors cause proteinuria, cerebral oedema and liver dysfunction and foetal growth restriction
Poor cardiac reserve can be due to maternal age, obesity, ethnicity, diabetes, auto-immune diseases, chronic hypertension and chronic kidney disease, also causing problems with cardiovascular function
this causes foetal growth restriction in the foetus
Maternal and foetal effects of pre-eclampsia
Maternal effects:
Cerebral oedema: eclampsia – Vasospasm: hypertension, renal failure – Endothelial injury: low platelets, disseminated intravascular coagulopathy (DIC) – Albumin leakage: proteinuria, pulmonary oedema
Foetal effects: Growth restriction Prematurity Placental abruption foetal death
What are some of the diagnostic criteria for pre-eclampsia
Hypertension Threshold >140/90 mmHg
Hypertension Baseline Normotensive <20 weeks (BUT can have superimposed PE on
background of Chronic HTN)
Proteinuria >300 mg/24 hrs OR Protein:Creatinine ratio (PCR) >30 mg/mmol
OR +2 urine dipstick
Proteinuria a prerequisite for diagnosis No
Other clinical criteria for diagnosis: Yes
- Renal Creatinine >90 μmol/litre
- Liver Liver enzymes: ALT or AST >40 IU/L, +/- RUQ or epigastric pain
- Neurological Eclampsia, altered mental status, blindness, stroke, clonus, severe
headaches or persistent visual scotomata - Haematological Platelets <150,000 x 109/L, Disseminated Intravascular
Coagulopathy (DIC) or haemolysis
- Uteroplacental Fetal growth restriction, abnormal umbilical artery Doppler
waveform analysis, or stillbirth.
Signs and symptoms of pe-eclampsia
• No symptoms • Headaches • Flashing lights • Epigastric pain • Nausea / vomiting • Confusion • Hypertension – Use the right cuff size – Disappearance of sounds • Proteinuria • Brisk jerks
What are some pre-eclampsia investigations
• 24-hr urinary protein OR spot protein:creatinine ratio • Platelet count • LFT - Liver enzymes (ALT) • U&E - Creatinine • Clotting tests • Fetal assessment – Ultrasound for growth and Dopplers +/- CTG
Antenatal management
Hospitalization is recommended for monitoring
• At least twice daily blood pressure
measurements
• PE bloods: frequency depends on the severity
• Symptoms of severe PE
Why not deliver the baby immediately
Complications of prematurity • Possibility of failed induction needing Caesarean section • Attempts to prolong pregnancy are justified for pre-term PE • Severe uncontrolled PE needs delivery after stabilization
Authors concluded that induction of
labour should be advised for women with
mild PE or mild gestational hypertension
at a gestational age beyond 37 weeks
Symptoms of severe pre eclampsia
Diastolic BP ≥ 110 mm X 2 • Systolic BP ≥ 160 mm X 2 and • ≥ ++ proteinuria • Signs or symptoms of imminent eclampsia – Hyper-reflexia (neuronal irritability) – Frontal headache – Blurred vision (cerebral vasospasm) – Epigastric tenderness (tension on liver capsule)
Medication for prevention of seizures in women with pre-eclampsia
Magnesium sulphate to women with preeclampsia
reduces the risk of an eclamptic seizure.
• Women allocated magnesium sulphate had a 58%
lower risk of an eclamptic seizure
(58% reduction 95% CI 40–71%).
• Maternal mortality lower in treatment group
(11/5055 vs 20/5055)
• Reduced risk of placental abruption
(RR 0.67, 95% CI = 0.45 – 0.89)
Describe post-natal management for pre-eclampsia
Carefully assess women with signs or symptoms of preeclampsia
• Assess need to continue anti-hypertensives
• Arrange appropriate follow-up
• An assessment of BP and proteinuria by the general
practitioner at the 6 weeks postnatal check is recommended.
• If hypertension or proteinuria persists then further
investigation is required.
Women whose pregnancies have been complicated by severe preeclampsia or eclampsia should be offered a formal postnatal review to discuss the events of the pregnancy. • Pre-conceptional counseling should be offered where the events that occurred, any risk factors and any preventative therapies can be discussed.
Summary of pre-eclampsia
Pre-eclampsia can kill • The severity and progression of the disease are variable • Both mother and fetus are at risk • Is a multi-organ disease • Severe pre-eclampsia needs multi-disciplinary input • The only cure is delivery
