Complications in pregnancy 2 Flashcards
(38 cards)
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
If a mother is diagnosed with pre-eclampsia during pregnancy what can be done to ensure the foetus reaches maturity before going ahead with delivery?
- Close observation of clinical signs and investigations
- Anti-hypertensives (labetolol, methyldopa and nifedipine)
- Steroids for foetal lung maturity if gestation <36 weeks
- Risks of pre-eclampsia may persist into the post-natal period therefore monitoring must be continued post delivery
Look
If a mother is diagnosed with pre-eclampsia during pregnancy the aim is to continue the pregnancy until foetal maturity is reached…
However, induction of labour / c-section should be considered if maternal or foetal condition deteriorates, irrespective of gestation!!
What is Eclampsia?
Eclampsia is defined as the occurrence of 1 or more convulsions in a pre-eclamptic woman in the absence of any other neurological or metabolic causes.
- It is an obstetric emergency affecting approximately 5/10,000 pregnancies, with a maternal mortality rate of 1.8% and a fetal mortality rate of up to 30%.
How are eclamptic seizures treated?
- Magnesium sulphate bolus + IV infusion
- Control of BP - IV labetolol, hydrallazine (if >160/110)
- Avoid fluid overload
What is the preventative medication given to pregnant women who have had pre-eclampsia in a previous pregnancy?
Low dose Aspirin from 12 weeks till delivery
What is Gestational diabetes?
- It is defined as ‘any degree of glucose intolerance with onset or first recognition during pregnancy’. It reverts to normal after delivery.
- Approx 1 in 5 pregnancies now affected.
- Untreated gestational diabetes can have severe untoward effects on the health of the mother and that of the developing fetus.
- Women who develop this are more at risk of developing type 2 diabetes later in life
Why does a mother’s insulin requirements increase during pregnancy if they have pre-existing diabetes?
Substances secreted from the placenta have anti-insulin actions such as:
- Human placental lactogen
- Human chorionic gonadotrophin
- Cortisol
Diabetes puts the mother at increased risk of…
- Having a miscarriage
- Polyhydramnios
- Operative delivery - early delivery / c-section
- Having a stillbirth
- Increased perinatal mortality
- Increased risk of pre-eclampsia
- Worsening of maternal pre-existing nephropathy, retinopathy, hypoglycaemia, reduced awareness of hypoglycaemia
- Infections
Diabetes during pregnancy puts the neonate at increased risk of…
- Impaired lung maturity + respiratory distress syndrome - the excess insulin in the baby’s body can delay production of the surfactant required for lung maturation
- Neonatal hypoglycaemia - due to raised insulin - the brain needs blood glucose to function so having an insufficient amount of glucose can harm the brain’s ability to function. Severe or long-lasting hypoglycemia may cause seizures and serious brain injury
- Jaundice
- Macrosomia + shoulder dystocia
- Premature birth - high blood sugar may increase women’s risk of early labour and delivery before the due date. Or early delivery may be recommended because the baby is large
- Still birth
- Congenital abnormalities/deformities
