Placental Dysfunction Flashcards
Give two implantation defects
- Ectopic pregnancy
- Placenta praevia
What is an ectopic pregnancy?
Implantation at a site other than uterine body
What is the most common implantation site in ectopic pregnancy?
Ampulla of Fallopian tube, but can also be peritoneal or ovarian
What is the problem with ectopic pregnancy?
If implantation not in endometrium, no decidual cells to control it, and so the invasive process can rupture the uterine tubes
What is vulnerable if there is rupture of the uterine tubes in an ectopic pregnancy?
Big vessels in the pelvis
What is there a risk of if the big vessels in the pelvis are affected in an ectopic pregnancy?
Haemoperitoneum
What is placenta praevia?
Implantation in the lower uterine segment
Where does the placenta grow in placenta praevia?
Across the internal os
What can placenta praevia cause?
Haemorrhage in pregnancy
What is necessitated in placenta prevaeia?
C-section delivery
Why is C-section delivery required in placenta praevia?
Because the internal os is occluded by the placenta, the birth canal is not functional
What happens in pre-eclampsia, with regard to elaboration of the spiral arteries?
There is inadequate modification of the vessels walls - invasion is not enough, so there is ineffective remodelling of the spiral arteries
Describe the epidemiology of pre-eclampsia
Most common condition related to morbidity and mortality in pregnancy in the developing world
What does pre-eclampsia lead to?
Poor growth and development of fetus, and maternal syndrome
What does placental insufficiency lead to?
Poor growth and development of the fetus
Give two forms of trophoblast disease
- Molar pregnancy (hydatidiform mole)
- Gestational trophoblast disease
What is gestational trophoblast disease?
When there is an overgrowth of placental tissue, but no embryo, so get very high hCG reading
What is choriocarcinoma?
A malignant version of gestational trophoblast disease
Why may hCG be monitored in choriocarcinoma?
To see how effective treatment is
What is the result of the placenta not being a true barrier?
Teratogens access the getus via the placenta quite easily
What teratogens can access the fetus via the placenta?
- Alcohol
- Therapeutic drugs
- Drugs of abuse
- Maternal smoking
What is the importance of alcohol in pregnancy?
It is a small molecule, so can easily access, and damages the CNS
When is the CNS vulnerable to damage?
Throughout gestation
What does maternal smoking affect in pregnancy?
Fetal growth and development
What can antibody transport cause in pregnancy?
Haemolytic disease of the newborn
When does haemolytic disease of the newborn arise?
When there is a rhesus group incompatability of the mother and fetus q
What happens in haemolytic diseease of the newborn?
Leakage of fetal blood into the maternal circulation
Why is haemolytic disease of the newborn now uncommon?
Because of prophylactic treatment when known rhesus incompatability
How are infectious agents taken up by the placenta?
Pinocytosis
What infectious agents can be taken up into the placenta?
- Varicella zoster
- Cytomegalovirus
- Treponema pallidum
- Toxoplasma gondii
- Rubella
What is happening to the incidence of It fetal rubella syndrome?
It is decreasing in incidence due to mass immunisation
What does rubella syndrome?
- Microcephaly
- PDA
- Cataracts
