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)