Hypertensive disorders in pregnancy Flashcards
Does blood pressure normally change during pregnancy?
Yes, falls in the second trimester by about 30/15. By term, blood pressure should be back to pre-pregnant levels.
How does pre-eclampsia cause HTN?
Largely due to increase in systemic vascular resistance. Protein excretion in normal pregnancy is increased, but not by much.
How can HTN in pregnancy be classified?
Pregnancy-induced HTN and pre-existing or chronic HTN.
What is pregnancy-induced HTN?
BP raises above 140/90 after 20 weeks, either transiently or due to PE.
What is preeclampsia (PE)?
HTN and proteinuria >0.3g/24h after 20w gestation, often with oedema
What is eclampsia?
The occurrence of epileptiform seizures, the most dramatic complication
Are patients with chronic HTN at increased risk of PE?
Yes, six fold more risk
What is the pathology of PE?
Systemic blood vessel endothelial cell damage, in association with an exaggerated maternal inflammatory response, leading to vasospasm and increased capillary permeability and clotting dysfunction.
What is the course of PE?
The disease is progressive, but variable and unpredictable. HTN usually precedes proteinuria.
Is PE more common in nulliparous or multiparous women?
It is less common in multiparous women unless additional risk factors at present
Is PE likely to recur?
There is a 15% recurrence rate; this is up to 50% if there has been severe pre-eclampsia before 28 weeks
What is mild PE?
Proteinuria and mild/moderate HTN
What is moderate PE?
Proteinuria and severe HTN (160/110)with no maternal complications
What is severe PE?
Proteinuria and any hypertensions <34 weeks or with maternal complications
What are the high risk factors for PE?
- hypertensive disease in a previous pregnancy
- chronic kidney disease
- autoimmune disease, such as systemic lupus erythematosus or antiphospholipid syndrome
- type 1 or type 2 diabetes
- chronic hypertension
What is HELLP syndrome?
A life-threatening pregnancy complication usually considered to be a variant or complication of pre-eclampsia
What are the symptoms of HELLP syndrome?
H (haemolysis): dark urine, raised LDH, anaemia
EL (elevated liver enzymes): epigastric pain, liver failure, abnormal clotting
LP (low platelets): normally self-limiting
What are the clinical features of PE?
Usually asymptomatic, but headache, drowsiness, visual disturbances, nausea/vomiting or epigastric pain may occur
What are the maternal complications of PE?
Eclampsia; cerebrovascular haemorrhage; liver and coagulation problems (HELLP); renal failure; pulmonary oedema
What is the pathology of eclampsia?
Generalised tonic clonic seizures, probably resulting from cerebrovascular vasospasm.
How does eclampsia cause mortality?
It can result from hypoxia and concomitant complications of severe disease
How do you treat eclampsia?
Magnesium sulphate, and intensive surveillance for other complications
How does eclampsia cause cerebrovascular haemorrhage?
Failure of cerebral blood flow autoregulation an mean arterial pressures above 140mmHg. Treatment of HTN should prevent this
How do you treat HELLP syndrome?
Supportive treatment and magnesium sulphate eclampsia prophylaxis. Intensive care treatment is required in severe cases
What are the fetal complications of PE?
IUGR; preterm birth; placental abruption and hypoxia
How do you investigate PE?
Exclude urine infection; urine protein:creatinine ratio is used to determine protein levels. Screen for maternal and fetal complications
What antihypertensive is recommended in pregnancy for PE?
Labetalol
How quickly do symptoms occur after proteinuria?
As a general rule, one or more fetal or maternal complication is likely to occur within 2 weeks
Does PE alter how the baby is delivered?
It can be either C section or vaginal if there is no urgency (complications). CTG is used to closely monitor the fetal heartbeat and blood pressure should be monitored during labour
What are the pitfalls in treating PE?
It is unpredictable HTN may be absent; watch for proteinuria LFTs must be performed with epigastric pain Severe HTN must be treated HTN treatment may disguise the PE Excessive fluids causes pulmonary oedema
Does PE stop as soon as the baby is delivered?
No, it can often take at least 24 hours and may worsen in this time so maternal monitoring needs to continue
What are the risk factors for pre-existing HTN?
Common in older and obese women with a positive family history or who developed HTN on combined oral contraceptive
Does pregnancy often alter pre-existing HTN?
HTN usually increases in late pregnancy
Are any HTN treatments teratogenic?
Yes, ACE inhibitors, use labetalol
List 6 moderate risk factors for PE.
- first pregnancy
- age 40 years or older
- pregnancy interval of more than 10 years
- body mass index (BMI) of 35 kg/m² or more at first visit
- family history of pre-eclampsia
- multiple pregnancy