Hypertension in Pregnancy Flashcards
What is the incidence of HT in pregnancy?
10-15%
What is the commonest cause of iatrogenic prematurity?
Pre-eclampsia
Describe BP throughout pregnancy
Falls in early pregnancy
Nadir reached at 22-24wks
Steady rise until term
Falls after delivery but rises and peaks at day 3-4 P/N
What are the risks associated with pre-existing HT?
PET x2
IUGR
Abruption
When will PIH occur and resolve?
Second half of pregnancy
Resolves within 6/52 PN
What are they key features of pre-eclampsia?
HT
Proteinuria (>=0.3g/l or >=0.3g/24hrs)
Oedema
What are some of the pathophysiological causes of pre-eclampsia?
Abnormal placentation and trophoblast invasion, leading to failure of normal vascular remodelling
Spiral arteries fail adapt to become high capacitance, low resistance vessels
Placental ischaemia, leading to widespread endothelial damage and dysfunction
Endothelial activation leading to increased capillary permeability, expression of CAM, prothrombotic factors, platelet aggregation and vasoconstriction
What are the CNS components of pre-eclampsia?
Eclampsia Hypertensive encephalopathy Intracranial haemorrhage Cerebral Oedema Cortical Blindness Cranial Nerve Palsy
What are the renal components of pre-eclampsia?
Decreased GFR
Proteinuria
Increased serum uric acid (also placental ischaemia) and creatinine/potassium/urea
Oliguria /anuria
Acute renal failure- acute tubular necrosis, renal cortical necrosis
What are the hepatic components of pre-eclampsia?
Epigastric/RUQ pain
Abnormal liver enzymes
Hepatic capsule rupture
HELLP syndrome: Haemolysis, Elevated Liver Enzymes, Low Platelets-high morbidity/mortality
What are the haematological components of pre-eclampsia?
Decreased PV Haemo-concentration Thrombocytopenia Haemolysis Disseminated Intravascular Coagulation
What are the cardiopulmonary components of pre-eclampsia?
Pulmonary oedema leading to ARDS- iatrogenic, disorder related
PE
High mortality
What are the placental components of pre-eclampsia?
IUGR
Placental abruption
IUD
What are the symptoms of pre-eclampsia?
Headache Visual disturbance Epigastric/RUQ pain Nausea/vomiting Rapidly progressive oedema
What are the signs of pre-eclampsia?
Hypertension Proteinuria Oedema Abdominal tenderness Disorientation SGA IUD Hyper-reflexia / involuntary movements / clonus
What Ix are required in pre-eclampsia?
Urea & Electrolytes Serum Urate Liver Function Tests Full Blood Count Coagulation Screen UPCR CTG Ultrasound - biometry, AFI, Doppler
How is pre-eclampsia managed?
Assess risk at booking HT at <20wks-look for 2' cause Antenatal screening- BP, urine, MUAD Treat HT Maternal & fetal surveillance Timing of delivery PIH can be managed as OP in Day Care Unit
What are the RFs for pre-eclampsia?
Maternal age (>40y: 2x) Maternal BMI (>30: 3x) FHx (20-25% if mother affected, up to 40% if sister) Parity (1st pregnancy 2-3x) Multiple pregnancy (Twins 2x) Previous PET (7x) Molar pregnancy/triploidy
What are the medical RFs for pre-eclampsia?
Pre-existing renal disease Pre-existing HT DM CTD Thrombophilias (congenital/acquired)
When should you refer to AN DCU?
BP >=140/90
Proteinuria ++
Oedema ++
Symptoms: esp persistent headache
When should you admit women with pre-eclampsia?
BP >170/110 OR >140/90 with (++) proteinuria
Significant symptoms - headache / visual disturbance / abdominal pain
Abnormal biochemistry
Significant proteinuria - UPCR >30mg/mmol
Need for antihypertensive therapy
Signs of fetal compromise
How should HT be treated in pregnancy?
Treat regardless of cause
With MAP of >=150mmHg significant risk of cerebral haemorrhage
BP >=170/110 requires immediate Rx
Aim for 140-150/90-100
When is methyl dopa contraindicated in HT treatment?
Depression
When is labetolol contraindicated in HT treatment?
Asthma
Are methyl dopa, labetolol, nifedipine SR and hydralazine safe in pregnancy?
Yes
When are most deliveries carried out after a pre-eclampsia diagnosis?
Within 2 wks of diagnosis
What are the indications for delivery in pregnancy with HT?
Term gestation Inability to control BP Rapidly deteriorating biochemistry / haematology Eclampsia Other Crisis Fetal Compromise - REDF, abnormal CTG
What are some crises in pre-eclampsia?
Eclampsia HELLP syndrome Pulmonary Oedema Placental Abruption Cerebral Haemorrhage Cortical Blindness DIC Acute Renal Failure Hepatic Rupture
What is eclampsia?
Tonic-clonic (grand mal) seizure occurring with features of pre-eclampsia
How many women will have eclampsia seizure before onset of proteinuria/HT?
> 1/3
In what age group is eclampsia more common?
Teenagers
What antihypertensives are used in eclampsia?
IV Labetolol
IV Hydralazine
(beware hypotension-fetoplacental unit)
What is the treatment and prophylaxis for eclampsia seizure?
Magnesium Sulphate: Loading dose 4g IV over 5mins Maintenance IV infusion 1g/h If further seizurs 2g MgSO4 If persistent consider diazepam 10mg IV
What is the main cause of death in eclampsia?
Pulmonary oedema
What is the safe option in fluid administration in eclampsic patients?
Run patient dry- 80ml/hr
Fluid challenges can be dangerous
What should be checked when there is any doubt about renal function in an eclampsic patient?
Urine osmolality
Does oliguria require intervention in eclampsia?
No- occurs in 30%
Describe labour and delivery in eclampsia
Aim for vaginal delivery if possible Control BP Epidural anaesthesia Continuous electronic fetal monitoring Avoid ergometrine Caution with iv fluids
When is aspirin used in pre-eclampsia?
High risk women- renal, DM, APS, multiple RFs, previous PET
Commence before 12 weeks (75mg)
