Pathologies of Pregnancy Flashcards
When do the hormones peak in a normal cycle
- Day 0-14 - oestrogen peaks
- Day 14-28 - Progesterone peaks
What does progesterone do
- Thickens the lining of the endometrium
- Changes cells in the endometrium
- Turn endometria into decidua
- Increases vascularity
- Between glands and vessels the stromal cells enlarge and become procoagulant –> stops bleeding
What is another name for the egg
- Chorion
What surrounds the outer edge of the chorion
- Trophoblast cells (placental cells) on teh oustide
- Produce beta-human chorionic gonadotrophin (B-hCG)
What happens once the egg is fertilised
- Fertilised egg burrows into decidua
- Trophoblast cells stream off to invade mothers blood vessels and eventually link them to the foetus
- Eventually the chorionic villi, covered by trophoblast cells, are bathed in the mothers blood, forming forerunner of placenta)
- Decidual stroma cells are procoagulant and stop trophoblast cells causing too much bleeding
What is B-hCG
- Target is corpus luteum in ovary
- Function is to stimulate corpus luteum to produce progetserone, which stops decidua from shedding
- Forms basis of pregnancy tests
- Stimulates the ovary to produce progesterone throughout pregnancy, preventing the decidua from shedding
What is an ectopic pregnancy
- Pregnancy in the wrong anatomica site
- If early, woman may not even know she is pregnant
What occurs in an ectopic pregnancy
- Lack of proper decidual layer and small size of tube predispose to haemorrhage and ruputre
Where is the most common location for ectopic pregnancy
- fallopian tube
What occurs in a normal ovary
- Mother switches off certain genes in ova (eggs) by methylating them
- Father switches off different genes in sperm by methylating them
How do gene changes growth in pregnancy
- Mothers changes promote early baby growth
- Fathers changes promote early placenta growth via trophoblast proliferation
What are the causes of a molar pregnancy
- Most often caused by 2 sperm fertilising with 1 egg and no chromosomes
What does a molar pregnancy result in
- Imbalance in methylated (switched off) genes
- Resulting in trophoblast overgrowth –> overgrowth of placenta
What are the groups of trophoblast cells
- A form of pre-cancer
- If it persists can give rise to malignant tumour - choriocarcinoma
Treatment of molar pregnancy
- If B-hCG return to normal - no further treatment
- If B-hCG stays high (persistent disease) cure by methotrexate
What is the pathophysiology of DM in pregnancy
- Effects of too much glucose in mother
- Decrease in insulin in mother –> increase in glucose in mother –> crosses placenta –> increase in glucose in baby –> increase in insulin of baby
- Baby reduce own glucose as mother keeps sending more across placenta
- Leads to massive growth –> susceptible to intrauterine death
Problems of DM in pregnancy
- Malformations
- Huge babies that obstruct labour
- Intrauterine death (sudden metabolic and hypoxic problems)
- Neonatal hypoglycaemia
What is acute chorioamnionitis
- Ascending infection
- Bacteria are typically perineal or perianal flora (e.g. E. coli)
- Ascend vagina and then amniotic sac
Presentation of acute chorioamnionitis
- Mother ill - has fever and raised neutrophils
- Mother well
- In baby
- Intrauterine death
- Ill in 1st days life
- Cerebral palsy
What happens in the baby’s brain in acute chorioamnionitis
- Neutrophils produce cytokine ‘storm’
- Activates some brain cells which then get damaged by normal hypoxia of labour
What is placental abruption
- Separation of placenta from uterine wall
- Bleeding can collect and cause haematoma
What does placental abruption result in
- Hypoxia for baby
- Can cause antepartum haemorrhage in mother
Causes of placental abruption
- Hypertension
- Trauma
- Other e.g. cocaine
