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