Pregnancy and Pre-eclampsia Flashcards
what do the trophoblast cells go onto become?
Placenta
What does the inner cell mass go onto become?
forms the embryo and extraembryonic structures
what are the 2 layers of the trophoblast cells? briefly describe them
Outer: syncytiotrophoblast cells - non-dividing, multinucleated
Inner: cytotrophoblast cells - proliferative
lacunae (fluid filled spaces) are precursors to ____?
intervillous spaces
by what week do tertiary villi form?
Week 3
What do tertiary villi consist of?
An outer monolayer of syncytiotrophoblast
Invaded by an inner layer of cytotrophoblast cells
Vascularised with fetal capillaries.
fetal placenta = ____ plate
Maternal placenta = ____ plate
fetal - chorionic
materna - basal
Define pre-eclampsia
new onset hypertension (systolic >140 or diastolic >90 mmHg) occurring after 20 weeks’ gestation with oedema and new proteinuria (protein:creatinine ratio >30mg/mmol)
Define eclampsia
Fits/convulsions associated with the features of pre-eclampsia
Define Fetal Growth Restriction
Failure of the fetus to reach its ‘genetically predetermined growth potential’
If eclampsia is severe, what can it lead to?
If severe, can cause maternal and/or fetal death
what are the implications of PE?
pre-term birth
maternal and perinatal morbidity and mortality
what is a pre-term birth?
Delivery at <37 weeks gestation
what are the implications of FGR?
Results in birthweight below the 5th centile of individualised birthweight ratio (IBR) charts
Stillbirth
If they survive: increased risk of neonatal and adulthood diseases
list the factors that have a role in pre-eclampsia
genes
placenta
immune response
maternal vascular disease
what is the cure for eclampsia and what consequences does this have?
cure = iatrogenic preterm delivery
complications: stillbirth
What are women with hypertensive disorders of pregnancy more likely to develop?
cardiovascular (heart) disease in later life
What are clinical features of PE?
Hypertension
Proteinuria
Oedema – hands, feet, face
Consequence of endothelial dysfunction
what are risk factors for pre-eclampsia?
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)
List the 3 steps in hypothesis of Pre-eclampsia
Abnormal placentation
Abnormal maternal response (to placental trigger)
Organ/systems failure
Describe the abnormal placentation stage in pathophysiology of Pre-eclampsia
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.
Describe the abnormal maternal response stage in pathophysiology of Pre-eclampsia
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
Describe the endothelial dysfunction stage in pathophysiology of Pre-eclampsia
The exaggerated inflammatory response leads to endothelial dysfunction (defective proliferation/survival of endothelial cells)
Define endothelial dysfunction
a systemic pathological state, characterised by imbalance between vasodilator and vasoconstrictor molecules produced by or acting on the endothelium
