Common Pathologies of Pregnancy Flashcards
If the egg is fertilised what happens to progesterone?
It doesn’t dip
It turns the endometrium into the decidua by increased endometrial thickness, vascularity and enlarging the stromal cells between vessels and making them become anticoagulant
What is another name for the egg?
Chorion
What lines the outer aspect of the chorion?
Trophoblast cells
What is the function of trophoblast cells?
Production of beta-hCG which stimulates the CL to produce progesterone that stops the decidua shedding
What hormone is picked up in pregnancy tests?
b-hCG
What is the decidua?
Endometrium during pregnancy (forms maternal part of placenta)
How is the placenta formed?
Fertilised egg borrows into decidua
Chorionic villi covered in trophoblast cells invade mothers vessels
Decidual stromal cells are procoagulant and prevent excess bleeding
Eventually chorionic villi are bathed in mother’s blood
Why is are the tubes more prone to rupture in ectopic pregnancy as opposed to uterine pregnancy?
Tubes lack proper decidual layer (so trophoblasts invade into mucosa and muscle) and also small size of tubes
Both predispose to rupture and haemorrhage
What happens in normal pregnancy in terms of the egg and sperm’s genes and fusion of the gametes?
Mum and dad switch off certain genes in their gametes by methylation
Ovum and sperm fuse (23 chromosomes each)
Mum’s changes –> growth of the baby
Dad’s changes promote trophoblast proliferation and hence placenta formation
What are the causes of molar pregnancy?
Many causes but often caused by 2 sperm fertilising an egg with no chromosomes
What results in molar pregnancy?
Imbalance in methylation –> massive overgrowth of trophoblast cells and therefore overgrowth of placenta
What can molar pregnancy lead to?
It is a pre-cancer of the trophoblasts
Can lead to malignant choriocarcinoma
How do you manage molar pregnancy?
If b-hCG starts to return to normal can leave it
If b-hCG continues to rise then give methotrexate
Why do diabetic mothers have such big children?
Reduced insulin in mother –> high BG –> glucose crosses placenta –> high BG in baby –> high insulin in baby –> massive growth –> susceptibility to IUD
What complications can result of diabetes in pregnancy?
Malformations
Huge babies that obstruct labour
IUD (due to metabolic/hypoxic problems)
Neonatal hypoglycaemia (due to persistent hyperinsulinaemic hypoglycaemia)
How can diabetic mothers prevent complications to the baby?
Good glucose control
How does opiate use affect fetal development?
It doesn’t so long as mother eats well
But opiates cross placenta and will get immediate heroine withdrawal at birth and later withdrawal from methadone (weeks later, overfeeding, constant mouthing movements etc.)
How do you manage heroine withdrawal in a neonate?
Phenobarbitone and wean off
What must you be mindful of when treating withdrawal?
Can seizure
How does cocaine affect your BVs?
Vasoconstrictor
Constricts BVs of the septal cartilage –> collapse of bridge of nose
Constricts BVs of heart –> scarring and death
In pregnancy, constricts BVs to uterus
How many doses of cocaine is necessary to cause damage to the foetus?
Only 1
Could constrict vessels to uterus during kidney/eye/limb formation etc. –> abnormalities
Apart from foetal abnormalities, what else can cocaine use during pregnancy increase the risk of?
Placental abruption and foetal death
What is the commonest cause of IUD and neonatal illness?
Overtwisted cord
What causes overtwisted cord?
Tends to be happy, healthy babies moving around a lot and turning their own cord
What can overtwisted cord lead to?
IUD, hypoxic baby
Can cause foetal death from 15wks –> term
What does an overtwisted cord look like?
Twists every 1.5-2cm as opposed to 5-6cm
Dark as opposed to light in colour
What is placental abruption?
Separation of placenta from uterine wall –> bleeding/haematoma
What are the consequences of placental abruption for the baby?
Hypoxic, IUD, seizures, lactic acidosis
What can cause placental abruption?
HTN, trauma, cocaine
Define pre-eclampsia
HTN leading to kidney disease (proteinuria)
What are the consequences of pre-eclampsia?
Can get huge loss of albumin
HTN in pregnancy can lead to liver damage –> HELLP syndrome
Intracranial bleeds/strokes due to HTN in brain
What is the aetiology of pre-eclampsia?
Placenta normally chews away at the smooth muscle around mum’s BVs so they can’t constrict and reduce BF to the uterus
In pre-eclampsia, there is failure to do this, and so placenta goes through periods of being well and poorly perfused
Placenta then produces hormones to make mum hypertensive so it is always well perfused
