4.2 - Hypertension in Pregnancy Flashcards
What is the definition of chronic HTN?
140/90 persistently
Define Gestational Hypertension
BP>140/90 on 2 occasions, 4 hours apart + >20 weeks gestation
Define Pre-eclampsia
BP >140/90, on 2 occasions, 4 hours apart > 20 weeks gestation
+ Significant Proteinuria (>300mg/24 hours or Protein:Creatinine >30)
OR + Evidence of maternal end-organ dysfunction without other identified causes
1) Renal: Acute tubular necrosis with Creatinine >90
2) Liver: Subscapular haematoma => RUQ/Epigastric pain + raised ALT/AST
3) Neurological: Eclampsia (seizures), Visual disturbances, clonus, stroke, headaches
4) Haematological: Thrombocytopenia, DIC, and Intracranial haemorrhage
5) Uteroplacental insufficiency => IUGR, Abnormal doppler US
1% of patient with Pre-eclampsia end up with Eclampsia. Define Eclampsia
Seizures occurring in pre-eclampsia that cannot be attributed to other causes
Every seizure in pregnancy is considered pre-eclampsia until proven otherwise such as hypoglycemia, or previous hx of epilepsy
In obstetrics, what period is most likely for seizures?
Post-partum period
State the 6 Risk factors for Pre-eclampsia
High Risk =1
1) Chronic HTN
2) Hx of Pre-eclampsia in previous pregnancy
3) CKD
4) T1/T2DM
5) Autoimmune diseases (SLE, APS)
Moderate risk =0.5
1) Family hx of Pre-eclampsia
2) Multiple Pregnancy
3) BMI >35
4) Age >40
5) Nulliparous
6) Pregnancy interval >10 years
7) IVF Therapy
What are the indications of aspirin prescription in pregnancy? (3)
When must aspirin be given for maximum effectivity and what dose is prescribed?
1) PET Prevention (e.g. any rf present)
2) History of miscarriage/pregnancy loss
3) APS
4) Prevention of foetal growth restriction
<16 weeks at a dose of 75mg
What is the rationale for giving Aspirin for the prevention of pre-eclampsia
Inhibits COX 1 which inhibits the synthesis of platelet Thromboxane A2 which is responsible for reducing thrombosis (APS) and inflammation and hence improves uteroplacental blood flow => preventing pre-eclampsia => preventing IUGR as well.
Describe the pathophysiology of pre-eclampsia
Vascular theory: Normally, trophoblasts in early gestation causes vasodilation and reduced resistance to increase blood supply to the foetus. In Pre-eclampsia, there are much less trophoblasts => spinal arteries do not vasodilate as much and hence placental ischemia and necrosis leading to endothelial activation leading to inflammation and clots.
Immune theoary: Maternal alloimmune reaction is triggered by rejection of foetal allograft
What is HELLP Syndrome?
This is a complication of severe pre-eclampsia characterised by
1) Haemolysis
2) Elevated liver enzymes
3) Low Platelets
Give 4 clinical signs, 5 biochemical signs and 2 foetal signs of severe pre-eclampsia
It is literally part of the diagnosis of Pre-eclampsia. So just think of that and you will get most if not all
Clinical:
BP>160/110
CNS sx (headache/visual disturbance)
Clonus/hyperreflexia
Pulmonary oedema
Epigastric/RUG pain
Biological signs:
Oliguria (<500ml in 24 hrs)
Proteinuria (>5g in 24 hours compared to 300mg for diagnosis)
H: Hemolysis => reduced Hb
EL: Elevated Liver Enzymes => increased AST/ALT
LP: Low platelets
Foetal:
IUGR
Oligohydramnios
Abnormal foetal doppler
Give 6 complications of Pre-eclampsia
Maternal:
1) Eclampsia
2) DIC/HELLP
3) Pulmonary oedema
4) Placental abruption
5) Acute renal failure
6) Stroke
7) Liver failure/haemorrhage
Foetal:
1) preterm delivery
2) IUGR
3) Hypoxic ischemic encephalopathy
4) Perinatal death
A patient with diagnosed pre-eclampsia suddenly becomes hypotensive, light-headed, tachycardic, and tachypneic. What is the likely etiology of this?
Subcapsular hematoma
State the investigations you would like to carry out for a patient 31 weeks gestation presenting with blurred vision and a family hx of HTN. For each investigation, state your expected findings
1) HELLP:
FBC: reduced Hb, reduced platelets
LFT: increased transaminases (ALT/AST)
Coag screen: for DIC. Extended PTT/APTT
2) Kidney:
U&E: increased Urea and creatinine => renal compromise
Urinalysis (Proteinuria +1 or more)
PCR: Protein-Creatinine ratio >30/24 hour urine collection (>300mg/>5g)
MSU: rule out UTI
3) Imaging:
Ultrasound checking for IUGR (AC,HC, femur, BPD)
+ UA/MCA doppler
Delivery is the only curative management for Pre-eclampsia. When are you aiming for delivery in Pre-eclampsia?
37 weeks
unless severe/foetal compromise then before
