Some Common Pathologies of Pregnancy Flashcards
What does progesterone do to the endometrium?
Turns it into the decidua:
Thickens the lining
Increases the vascularity
Enlarges the stromal cells that become procoagulant and stop bleeding
What cells produce beta-human chorionic gonadotropin (B-hCG)? Where are they found?
Trophoblast cells
Found on the outside of a fertilized egg (chorion)
What is the target of B-hCG? (HCG) What is the function of the hormone?
The corpus luteum
Functions to ensure the corpus luteum is maintained and continues producing progesterone
What hormone is tested for in pregnancy tests?
Beta - human Chorionic Gonadotropin
B-hCG
What happens to the egg after fertilization?
Burrows into the decidua (modified endometrium)
Once inside the decidua what happens to the fertilized egg?
The trophoblast cells on its surface migrate to invade the mothers blood vessels and eventually link these vessels up with those of the fetus
Decidual stromal cells between the vessels of the decidua are anticoagulant and stop too much bleeding from occurring
How is the placenta originally formed??
Projections of the chorion (chorionic villi) covered in trophoblast cells move into the decidua. The trophoblasts invade the mother’s blood vessels
Eventually the chorionic villi, covered in trophoblast cells and covered in the mothers blood, become the forerunner of the placenta
If there is vaginal bleeding weeks after first missed period of pregnancy and then no baby is seen on USS, what could be the diagnosis? What could have caused this?
Miscarriage
- Fetal problem (eg. chromosomal abnormality)
- Placenta / membranes / cord problem (eg. infection)
- Uterus / cervix problem
- Maternal health issues (eg. drug taking)
Woman who is 8 weeks pregnant, small amount of bleeding from vagina, thickened lining of endometrium and expanded fallopian tube on 1 side. Diagnosis?
Ectopic pregnancy
How would a ruptured ectopic pregnancy present?
- Severe abdominal pain
- Tachycardia, hypotension
- On emergency laparotomy: litres of blood in abdomen.
Would expect to find fragmented fallopian tube with placenta and sac
What is an ectopic pregnancy?
Pregnancy in the wrong anatomical site
Most common site is the fallopian tube but no the only site
Why is an ectopic pregnancy so dangerous?
Lack of proper decidual layer (anticoagulant stromal cells) predisposes the woman to rupture and haemorrhage when the chorion and trophoblasts invade the tissue
What is a molar pregnancy?
A pregnancy in which an abnormal egg implants in the womb, the cells that should become the placenta grow far too quickly and take over the space where the embryo would normally develop
What causes a molar pregnancy?
In normal pregnancy:
- Egg has methylated genes encouraging early baby growth
- Sperm has methylated genes for early placenta growth via placenta proliferation
- Balance between the two
Molar pregnancy has many possible causes, but mostly 2 sperm fertilizing an empty ovum (no genes). Results in no viable egg but a proliferation of chorionic villi
What can a molar pregnancy progress into if it is untreated?
A choriocarcinoma (molar preg is a precancer of trophoblast cells)
Treated via obstetrician removal of endometrial tissue and cancer
How is a molar pregnancy treated?
- Removal of endometrial tissue by obstetrician
- If B-hCG remains elevated treat with methotrexate
How can a mother having poorly treated diabetes lead to increase risk of IUD (intra-uterine death)?
Glucose crosses the placental barrier causing a raise in the baby’s insulin.
The baby can’t compensate for the high glucose with a raise in insulin though, because the mother keeps sending more insulin across the placenta
Results in large, broad shoulder baby that is often stillborn
What are some possible complications of poor diabetic control during pregnancy?
1st trimester - malformations
3rd trimester - intrauterine death (probable sudden metabolic and hypoxic problems)
Labour - Huge babies that obstruct labour
Neonatal period - hypoglycaemia
What is chorioamnionitis? What causes it?
Inflammation of the cord and fetal plate of the placenta (neutrophils seen on microscopy)
Usually caused by ascending infection of the perineal or perianal flora which ascend the vagina and get into the amniotic sac
How can chorioamnionitis affect the baby?
Can cause intrauterine death
Can cause severe illness in first days of life: neonatal unit
Cerebral palsy later in life
How does chorioamnionitis present in the mother?
- Illness (sometimes)
- Fever
- Raised neutrophils
How does chorioamnionitis affect the baby’s brain?
Neutrophils produce cytokines that activate some of the brain cells
These brain cells are then damaged by the normal hypoxia of labour
If the mother is addicted to opiates or other drugs, what needs to be done by the hospital?
Baby must be born close to the neonatal unit and admitted to the unit immediately after birth for heroin withdrawal
What is the commonest cause of intrauterine death and neonatal illness? What is it (probably) caused by?
Over-twisted umbilical cord
Probably caused by normal baby movement and twisting round its own cord
What is abruption? How is it treated?
Separation of the placenta from the uterine wall
Usually causes a haematoma and needs to be treated with an urgent C-section
Complications of abruption in pregnancy?
Can expose the baby to hypoxia - complications depend on severity
Often causes antepartum haemorrhage in the mother
Is there always vaginal bleeding associated with an abruption?
No, if the abruption occurs and the placenta remains attached on either side of it there is just a haematoma
Can have both an abruption and a haematoma
What are some causes of abruptions?
Maternal hypertension
Trauma
Others: eg. cocaine
What is a TOPFA?
Termination Of Pregnancy For Abnormality
Like aborting a downs syndrome child before birth because of it’s condition
