PIH, Pre-eclampsia and HELLP Flashcards
When do we class hypertension as pregnancy induced?
If it occurs AFTER 20 WEEKS
Before that it is just essential hypertension or ‘pre-existing hypertension)
How serious are PIH and pre-eclampsia in pregnancy?
They are the second highest cause of indirect maternal mortality in the UK
How should a woman with pre-existing hypertension’s medications change for pregnancy?
She should stop ACE-is and be started on B-blockers e.g. LABETALOL or CCB e.g. Nifedipine if the B-B is CI’d
What is the difference between PIH and pre-eclampsia/
Pre-eclampsia is hypertension PLUS PROTEINURIA
What is thought to be an associated etiological factor in pre-eclampsia?
Poor trophoblast infiltration into the placenta during the first half of pregnancy
Impaired placental dysfunction and widespread vascular endothelial dysfunction
What are the two phases of the pathophysiology of pre-eclampsia?
- Poor trophoblast infiltration. During normal development trophoblasts invade maternal spiral arteries causing them to increase their diameter so that the flow of blood becomes low resistance and high flow - doesn’t happen as well in pre-eclampsia
- Reduced placental perfusion leads to placental ischaemia. This leads to endothelial dysfunction which causes changes such as maternal inflammatory response and reduced perfusion to the organs. Also over-activation of the coagulation system
Why does pre-eclampsia only really occur after 20 weeks?
Due to the physiological drop in blood pressure in the first trimester of pregnancy
How much protein has to be in the urine for it to be classed as proteinuria?
> 300mg/L
What are some risk factors for pre-eclampsia?
First pregnancy
FH (mother or sister with pre-eclampsia)
Extremes of maternal age
Obesity
PMH (Pre-existing HTN, Renal disease, thrombohphilias, SLE and DM)
Obstetric Hx: Multiple pregnancies, previous pre-eclampsia, hydatidiform mole, triploids, hydros fetalis, inter-pregnancy interval of >10y
What is eclampsia?
A seizure state associated with the feature of pre-eclampsia
How does blood pressure change in the normal pregnancy?
Fall slightly during first trimester (due to drop in SVR), reach lowest point at 22-24 weeks after which is steadily increases
How do we define hypertension in pregnancy?
> 140/90mmHg on more than 2 occasions more than 4 hours apart
OR >160/>110 mmHg on one occasion
OR Systolic >30mmHg above the booking blood pressure
What are some indications for admission in women with pre-eclampsia?
Blood pressure >170/110mmHg or >140/90 with 2+ protein
Those with significant symptoms: Headaches, visual disturbances, epigastric pain, oedema
Abnormal biochemistry
Need for treatment
Signs of fetal compromise
What are the principles of management in pre-eclampsia?
Get maternal BP <110mmHg with labetalol, nifedipine, hydralazine or methyl-dopa
Make regular assessment of the woman’s fluid balance- pre-eclampsia can change vascular permeability
MgSO4 can be given to reduce seizure risk
What is the cure for pre-eclampsia? When is this done?
DELIVERING THE BABY
Usually it is tried to get the woman to 34 weeks before delivering her
What can we do to help prevent the development of pre-eclampsia?
Prophylactic aspirin treatment
Calcium supplementation
How should and eclamptic seizure be managed?
Turn the woman to her Left to prevent aorta-caval compression
Secure airway and administer oxygen
MgSO4 IV and monitor for signs of toxicity (Calcium gluconate can be given as reversal for MgSO4)
URGENT DELIVERY
When/how do we give the aspirin prophylaxis therapy?
75mg aspirin from 12w delivery
Also reduces the risk of pre-term birth and neonatal mortality
What does HELLP stand for?
Haemolysis, Elevated Liver enzymes, Low Platelets
Levels of what will we seeing rising in HELLP that we can measure?
Lactate Dehydrogenase - LDH (a key breakdown product during haemolysis - high levels as well as low Hb suggests breakdown of blood cells)
AST - this is the first liver enzyme to become elevated and the rest will follow (remember ALP will be high anyway as it is produced by the placenta)
How might HELLP syndrome present and who is it more common in?
Multiparous women - complication of pre-eclampsia
Usually it is found incidentally before symptoms start in women who are known to be pre-eclamptic and have their liver enzymes and platelets monitored but symptoms could include:
RUQ pain, epigastric tenderness and N&V
What are some complications of HELLP?
Acute renal failure
DIC
Increased incidence of placental abruption
How should HELLP be managed?
Try and correct disorder with coagulation and consider delivery as soon as possible
