Pregnancy and Pre-eclampsia

Question 1

what do the trophoblast cells go onto become?

Answer 1

Placenta

Question 2

What does the inner cell mass go onto become?

Answer 2

forms the embryo and extraembryonic structures

Question 3

what are the 2 layers of the trophoblast cells? briefly describe them

Answer 3

Outer: syncytiotrophoblast cells - non-dividing, multinucleated
Inner: cytotrophoblast cells - proliferative

Question 4

lacunae (fluid filled spaces) are precursors to ____?

Answer 4

intervillous spaces

Question 5

by what week do tertiary villi form?

Answer 5

Week 3

Question 6

What do tertiary villi consist of?

Answer 6

An outer monolayer of syncytiotrophoblast
Invaded by an inner layer of cytotrophoblast cells
Vascularised with fetal capillaries.

Question 7

fetal placenta = ____ plate

Maternal placenta = ____ plate

Answer 7

fetal - chorionic

materna - basal

Question 8

Define pre-eclampsia

Answer 8

new onset hypertension (systolic >140 or diastolic >90 mmHg) occurring after 20 weeks’ gestation with oedema and new proteinuria (protein:creatinine ratio >30mg/mmol)

Question 9

Define eclampsia

Answer 9

Fits/convulsions associated with the features of pre-eclampsia

Question 10

Define Fetal Growth Restriction

Answer 10

Failure of the fetus to reach its ‘genetically predetermined growth potential’

Question 11

If eclampsia is severe, what can it lead to?

Answer 11

If severe, can cause maternal and/or fetal death

Question 12

what are the implications of PE?

Answer 12

pre-term birth

maternal and perinatal morbidity and mortality

Question 13

what is a pre-term birth?

Answer 13

Delivery at <37 weeks gestation

Question 14

what are the implications of FGR?

Answer 14

Results in birthweight below the 5th centile of individualised birthweight ratio (IBR) charts
Stillbirth
If they survive: increased risk of neonatal and adulthood diseases

Question 15

list the factors that have a role in pre-eclampsia

Answer 15

genes
placenta
immune response
maternal vascular disease

Question 16

what is the cure for eclampsia and what consequences does this have?

Answer 16

cure = iatrogenic preterm delivery

complications: stillbirth

Question 17

What are women with hypertensive disorders of pregnancy more likely to develop?

Answer 17

cardiovascular (heart) disease in later life

Question 18

What are clinical features of PE?

Answer 18

Hypertension
Proteinuria
Oedema – hands, feet, face
Consequence of endothelial dysfunction

Question 19

what are risk factors for pre-eclampsia?

Answer 19

Primigravidae (1st pregnancy/first with new partner/first pregnancy in 10 years)
You, mother or sister have already had pre-eclampsia
Maternal age >40
BMI >35 or weight >90 kg
Multiple pregnancy
Existing hypertension, kidney problems and/or diabetes, thrombophilia (contributory not causative)
(Some evidence that women pregnant from egg donation are more susceptible)

Question 20

List the 3 steps in hypothesis of Pre-eclampsia

Answer 20

Abnormal placentation
Abnormal maternal response (to placental trigger)
Organ/systems failure

Question 21

Describe the abnormal placentation stage in pathophysiology of Pre-eclampsia

Answer 21

Normally, spiral arteries are remodelled from low flow, high resistance to become wider, high flow, low resistance channels.

In PE: there is reduced trophoblast invasion and abnormal spiral artery remodelling - it is incomplete.

This leads to impaired uteroplacental blood flow.

Question 22

Describe the abnormal maternal response stage in pathophysiology of Pre-eclampsia

Answer 22

fetoplacental circulation is compromised = hypoxia and/or ischaemia-reperfusion injury

–> release of free radicals and inflammatory mediators in the syncytiotrophoblast

–> excess release of placental factors: soluble fms-like tyrosine kinase 1 (sFLt1) and soluble endoglin (sENG), which sequester (remove) circulating vascular endothelial growth factor (VEGF) and placental growth factor (PlGF)

Leads to reduced concentrations of VEGF and PlGF in maternal plasma

Question 23

Describe the endothelial dysfunction stage in pathophysiology of Pre-eclampsia

Answer 23

The exaggerated inflammatory response leads to endothelial dysfunction (defective proliferation/survival of endothelial cells)

Question 24

Define endothelial dysfunction

Answer 24

a systemic pathological state, characterised by imbalance between vasodilator and vasoconstrictor molecules produced by or acting on the endothelium

Question 25

what does endothelial dysfunction manifest as?

Answer 25

Manifests as renal and cardiovascular dysfunction

Question 26

Describe the steps in the clinical management of Pre-eclampsia

Answer 26

reduce risk of hypertensive disorders before and during pregnancy

Help to diagnose PE:
Placental growth factor based testing is used to rule OUT PE.
Full clinical assessment

treatment

fetal monitoring

timing of birth: check if features of severe PE are present to see if she should consider planning an early birth

Advice on future risks of PE (likelihood of recurrence)

Question 27

What is assessed in a full clinical assessment for PE?

Answer 27

sustained high BP
concerning result of biochemical investigations e.g. rise in creatinine, ALT or fall in platelet count
signs of impending eclampsia or pulmonary oedema

Question 28

Describe the treatment plan for PE

Answer 28

offer labetalol (Beta blocker) to treat hypertension 
Offer nifedipine (Ca2+ channel blocker) if above is not suitable 
Offer methyldopa if both of above are not suitable

Question 29

what is involved in fatal monitoring ?

Answer 29

Cardiotocography (assess fetal heartbeat)

Ultrasound for fetal growth and amniotic fluid volume assessment

Umbilical artery Doppler velocimetry