L20 - Early pregnancy problems Flashcards
1. Briefly overview normal embryo transport and implantation within the uterus 2. Define the types of miscarriage 3. Define recurrent miscarriage and discuss the known genetic, immune and biochemical causes 4. Describe the normal anatomy of the Fallopian tubes and the common sites of implantation of ectopic pregnancies and clinical risk factors for this condition. (50 cards)
Recap the events that occur in the 2nd week of pregnancy? (4)
- Embryoblast, 2 layers: epiblast & hypoblast
- Trophoblast, 2 layers: cytotrophoblast & syncytiotrophoblast
- Yolk sac, 2: primary & secondary
- Cavities, 2: amniotic & chorionic
Describe when and how the blastocycst adheres to the uterine wall?
end of 1st week.
- Contact with uterine endometrium induces trophoblast at embryonic pole to proliferate.
- Some of these proliferating cells lose their cell membrane, coalesce to form the syncytium.
What is the synctiotrophoblast?
Mass of cytoplasm containing number of dispersed nuclei.
Describe the cytotrophoblast?
Cell of trophoblast that line the wall of the blastocyst retain their cell membrane.
What occurs between day 6-9 of pregnancy?
- Embryo fully implanted in endometrium.
- cytotrophoblast —secretes—> proteolytic enzymes
- to break down the ECM between endometrial cells.
How is the yolk sac formed?
Formed from the proliferation of hypoblast cell.
What layers must maternal and foetal blood flow through? (4)
- Endothelium of villus capillaries
- Loose connective tissue in core of the villus (extraembryonic mesoderm)
- Layer of cytotrophoblast
- Layer of synctiotrophoblast
Describe a hydatidiform mole?
signs / symptoms
- Pregnancy without embryo.
- Causes excessive nausea and vomitting
- due to excessively high levels of hCG.
Describe partial hydatidiform mole?
- Presence of typical nucleated embryonic erthryoblasts in molar villi
- presence of fetal BV indicate embryo was once present.
Define spontaneous miscarriage?
- Fetus dies or delivers dead
- before 24 completed weeks of pregnancy.
State the different types of miscarriage?
Threatened Inevitable Incomplete Complete Septic Missed
Threatened miscarraige
Bleeding, fetus still alive, os closed
Inevitable miscarriage
Heavier bleeding, fetus may be alive, os open, miscarriage about to occur.
Incomplete miscarriage
Some fetal part have been passed.
os usually open.
Complete miscarriage
All foetal tissue passed, bleeding has dimished, uterus no longer enlarged.
Cervical os is closed.
Septic miscarriage
Endometritis
Tender uterus
Infection
Missed miscarriage
Fetus not developed / died in utero, but not recognised until bleeding occurs.
Recurrent miscarriage
3 or more in succession.
Ectopic pregnancy
Embryo implants outside uterine cavity.
A patient with an ectopic pregnancy may present with…
- Lower abdominal pain.
- Dark vaginal bleeding.
What may be the medical management for an ectopic pregnancy?
- Ectopic unruptured, no cardiac activity: single does of methotrextate.
- Subsequent monitoring of hCG levels are important
Hyperemesis Gavidarum
Nausea, vomiting in early pregnancy.
Very severe.
Cause severe dehydration, weight loss of electrolyte imbalance.
What is gestational trophoblastic disease?
where does GTD begin?
- Normal development: trophoblastic cells form villi which grow into lining of uterus. This layer will develop into placenta.
- GTD begins in this layer of cells.
- HCG produced in excess
Briefly describe hydatidiform moles?
Complete - PATERNAL! - when one sperm fertilise an empty oocyte - diploid - no fetal tissue Partial - triploid usually - derived from two sperm entering one oocyte.
