pregnancy pathologies Flashcards
describe the hormone levels in a normal ovarian cycle.
- oestrogen peaks about day 14
- progesterone rapidly increases from day 14 and decreases again by day 28 if pregnancy is not achieved
- if pregnancy is achieved, it continues beyond day 28
what does progesterone do once an egg has been fertilised?
thickens endometrial lining
converts it into decidua
stromal cells enlarge and become procoagulant -> cessation of menstrual periods
describe the chorion
outer edge contains trophoblast cells which produce beta- human chorionic gonadotrophin
what is the function of B-hCG?
stimulates corpus luteum to produce progesterone
stops decidua from shedding
what hormone forms the basis of pregnancy tests?
B-hCG
describe the process of implantation.
- chorion burrows into decidua
- trophoblast cells stream off to invade mother’s blood vessels and link them up with the foetus
- chorionic villi covered in trophoblast cells move into decidua
- decidual stromal cells are procoagulant and help stop bleeding when trophoblast cells invade mother’s blood vessels
- chorionic villi are bathed in mother’s blood forming the forerunner of the placenta
what is an ectopic pregnancy?
pregnancy which occurs in the wrong anatomical site
what is the most common site of ectopic pregnancy?
Fallopian tube
what predisposes to rupture in ectopic pregnancy?
Lack of proper decidual layer and small size of fallopian tube
what happens in normal pregnancy to promote growth of the baby and the placenta?
mum & dad switch off certain genes in egg/sperm by methylating them
mum -> promotes early baby growth
dad -> promotes early placenta growth via trophoblast proliferation
what is the pathogenesis behind a molar pregnancy?
2 sperm fertilising 1 egg with no chromosomes
results in imbalance of methylated genes -> trophoblast overgrowth
what can happen if a molar pregnancy persists?
form of precancer of trophoblast cells (choriocarcinoma)
how is a molar pregnancy treated?
removal of pregnancy
- if BhCG stays high (persistent disease) then methotrexate
what are the associated problems of diabetes in pregnancy?
- malformations
- huge babies that obstruct labour
- intra uterine death
- neonatal hypoglycaemia
what should those with diabetes do before becoming pregnant?
obtain good glucose control
why do women with diabetes tend to have macrosomic babies?
too much glucose in mother
crosses placenta -> raises babies blood glucose
insulin goes up in the baby
baby cannot reduce glucose as mum keeps sending more across the placenta
long-term high insulin and high glucose leads to massive growth
what can ascending infection in the mother cause ?
acute chorioamnionitis
how does chorioamnionitis lead to neurological damage in the foetus?
neutrophils produce a cytokine storm
activates brain cells which get damaged by normal hypoxia of labour
Do opiates cross the placenta?
Yes and baby can get addicted to them
How do opiate addicted babies usually do?
Pregnancy often goes well if mother is eating properly
How is an heroin addicted baby treated once it is born?
- Immediate withdrawal from heroin when the baby is born
- Later withdrawal from methadone
What is a placental abruption?
Separation of the placenta from the uterine wall
What effect does placental abruption have on the baby?
decreased oxygen supply -> hypoxia
What can placental abruption often cause in the mother?
antepartum haemorrhage
How can varying degrees of bleeding occur as a result of placental abruption?
separates in different places = different degrees of bleeding
what can cause placental abruption?
- hypertension
- trauma (including abuse)
- other: cocaine use
Give some causes of miscarriage.
- Chromosomal abnormality
- Infection
- Maternal issues such as ill-health, trauma or hormonal problems
How can chorioamnionitis present in the mother?
- well or ill
- fever
- raised neutrophils
how can chorioaminionitis present in the baby?
- IUD
- cerebral palsy
What are the typical organisms involved in chorioamnionitis?
perineal/perianal flora: E.coli
What is over twisted cord a common cause of?
IUD and neonatal illness
