Complications in pregnancy 2 Flashcards
What is the clinical definition of Chronic hypertension during pregnancy?
Hypertension is considered chronic if it is present pre-pregnancy or noticed <20 weeks gestation
What are the values for Mild, moderate and severe hypertension in pregnancy?
- Mild = 140/90
- Moderate = 150/100
- Severe = 160/110
What is Gestational hypertenison (also known as pregnancy induced hypertension)?
- New hypertension that develops after 20 weeks
- BP is more than 140/90
What is Pre-eclampsia? + clinical definition
Pre-eclampsia is one of several hypertensive disorders that can occur during pregnancy. There is new hypertension after 20 weeks also with significant proteinuria.
- Defined as a BP of 140/90 on two occasions more than 4 hours apart
- Proteinuria of more than 300 mgms/24 hours (protein urine > + protein:creatinine ration >30mgms/mmol)
By definition, what is considered significant proteinuria?
- A urine protein:creatinine ratio of more than 30 mg/mmol
or
- An Automated reagent strip urine protein estimation > 1+
or
- 24 hours urine protein collection >300 mg/ day
If a woman with chronic hypertension becomes pregnant what should be done to reduce the risk of pre-eclampsia during pregnancy?
- Ideally patients should have pre-pregnancy care
- Change anti-hypertensive drugs if indicated eg. - stop ACE inhibitors (eg. Ramipril / Enalopril cause birth defects and impaired growth)
- Change Angiotensin receptor blockers (eg losartan, Candesartan)
- Low dietary sodium
- Aim to keep BP < 150/100 (labetolol, nifedipine, methyldopa)
- Monitor for superimposed pre-eclampsia
- Monitor fetal growth
Pathophysiology of pre-eclampsia?
The exact mechanism of pre-eclampsia is unclear. It is thought to be caused by poor placental perfusion, secondary to abnormal placentation (formation/type/structure).
- In normal placentation, the trophoblast invades the myometrium and the spiral arteries of the uterus, destroying the tunica muscularis media. This renders the spiral arteries dilated and unable to constrict, providing the pregnancy with a high flow, low resistance circulation.
- In pre-eclampsia, the remodelling of spiral arteries is incomplete. A high resistance, low-flow uteroplacental circulation develops, as the constrictive muscular walls of the spiral arterioles are maintained.
- Results in increase in BP, combined with hypoxia and oxidative stress from inadequate uteroplacental perfusion
- This chronic ischaemia can cause foetal complications like intrauterine growth restriction or intrauterine death
Risk factors for pre-eclampsia
- First pregnancy
- Extremes of maternal age
- Pre-eclampsia in previous pregnancy
- Underlying medical disorders
- Chronic hypertension
- Pre-existing chronic renal disease
- Pre-existing diabetes
- Autoimmune disorders like SLE or antiphospholipid syndrome
- If you have had a pregnancy interval >10 years
- BMI >35
- FH of pre-eclampsia
- Multiple pregnancy
Pre-eclampsia is a multisystem multi-organ disorder. Which organs/systems does it affect?
- Renal
- Liver
- Vascular
- Cerebral
- Pulmonary
Pre-eclampsia is associated with a number of potentially serious maternal and fetal complications.
What are some of the possible complications for the mother and foetus?
Maternal
- Eclampsia - seizures
- Severe hypertension – cerebral haemorrhage, stroke
- HELLP (hemolysis, elevated liver enzymes, low platelets)
- DIC (disseminated intravascular coagulation) - abnormal blood clotting throughout the body
- Renal failure - Acute Kidney Injury
- Pulmonary odema, cardiac failure
- Adult Respiratory Distress Syndrome (ARDS)
- Death
Foetal
- Impaired placental perfusion => IU Growth Restriction, foetal distress, prematurity or increased Post-Natal mortality
What are the symptoms and signs of severe Pre-eclampsia?
- Headache
- Blurring of vision
- RIQ pain - hepatic ischaemia
- Lower abdominal pain
- Nausea / Vomiting
- Peripheral oedema
- Pulmonary oedema
- Severe hypertension - can be more than 160/110
- >3+ of urine proteinuria
- Clonus/brisk reflexes
- Reducing urine output
- Convulsions / seizures (Eclampsia)
What biochemical abnormalities are seen in severe pre-eclampsia?
- Raised liver enzymes
- Biliruben if HELLP present
- Raised urea and creatinine
- Raised urate
What haematological abnormalities are seen in severe pre-eclampsia?
- Low platelets
- Low haemoglobin
- Features of DIC (rare) i.e prolonged prothrombin time, rapidly declining plasma fibrinogen level and raised D-dimer etc
Management of / monitoring pre-eclampsia during pregnancy?
- Frequent BP and Urine protein checks
- Check symptomatology - headaches, epigastric pain, visual distrubances etc
- Check for hyper-reflexia (clonus) and tenderness over the liver
- Blood investigations - FBC, LFT, RFT (serum urea, creatinine, urate) or coagulation tests
- Foetal investigations - scan for growth, cardiotocography
What is the only ‘cure’ for pre-eclampsia?
Delivery of the baby and placenta