Placental and Gestational Disorders Flashcards
Placenta: Functions (3)
- establish effective communication between mother and the developing fetus while maintaining the immune and genetic integrity of both individuals;
- allows intimate apposition of maternal and fetal circulations for exchange of nutrients, oxygen, and waste products;
- secretes a variety of hormones including human chorionic gonadotropin (hCG)
Define
- Amnion
- Chorion
- What does the chorion attach to?
- Define Chorionic Villi
- inner layer of the membrane surrounding the developing fetus, forms the amniotic cavity
- outer layer of the surrounding the developing fetus, forms the amniotic cavity
- decidua (endometrium of pregnancy)
- Placenta composed of chorionic villi that sprout from the chorion to provide a large contact are between the fetal and maternal circulations
Chorionic Villi
- Histo look
- What are the two layers of epithelium?
- central stroma, w/ vascularity
2. syncytiotrophoblast, cytotrophoblast
Fetal Circulation
- Under normal circumstances, when do the maternal and fetal blood mix?
- What are the umbilical vessels?
- How does maternal blood move?
- never
- 1 vein (carries oxygenated blood to baby), 2 arteries (carries deoxygenated blood back to receive oxygen and nutrients
- enters placenta via endometrial arteries and leaves via endometrial veins
Spontaneous Abortion (Miscarriage)
- When does it usually occur?
- How often does it occur?
- What are more than half due to?
- What are some other causes?
- pregnancy loss before 20 weeks
- 1/3 of all pregnancies are lost (10-15% of recognized pregnancies)
- chromosomal abnormalities (tri/monosomy)
- Defective implantation, fetal abnormalities, maternal causes (inflammation, uterine deformity, DM, luteal-phase defects) unknown
Ectopic Pregnancy
- Define
- How often does it occur?
- Where?
- Predisposing Factors
- Presentation
- Complications
- implantation occurs outside uterus
- 1:150 pregnancies
- 90% fallopian tubes, 10% ovary/abdom. cavity; may also implant in corn (horn) of uterus
- inflammation and scarring (pelvic inflamm disease –> constrictions and fibrosis of fallopian tube); intrauterine devices can increase risk
- abdominal pain, acute abdomen
- rupture and hemorrhage (esp of fallopian tube)
Twin Placentas
- 3 types of twin placentas
- What implies monozygotes?
- What determines the number of amnions?
- diamnionic, dichorionic; diamnionic, monochorionic; monoamnionic, monochorionic;
- monochorionic placenta; however, dichorionic can also be identical twins
- time of splitting of ovum
When does to ovum split to create:
- dichorionic, diamnionic placenta?
- monochorionic, diamnionic placenta?
- Monochorionic monoamnionic placenta?
- day 0-4
- day 4-8
- day 8-12
Twin-Twin Transfusion
- What happens?
- What happens to each twin?
- 1 fetus gets more blood than the other
2. the less perfused twin often does not survive; well perfused twin may not make it as well
Placenta Previa
- Define
- Symptom
- how is baby delivered?
- Risk factor?
- attachment of placenta to lower uterine segment or cervix
- painless, serious 3rd trimester bleeding due to dilatation of cervix;
- C-section
- previous C-sections
Placenta Accreta
- Define
- Causes what?
- What can it do?
- Predisposing factors
- partial or complete absence of decidua with adherence of placental villous tissue directly to myometrium (failure of placental separation)
- post-partum bleeding
- Can invade into other structures, like the bladder
- Placenta Previa, previous C-section (scarring of endometrium)
Abruptio Placentae
- Define
- What forms?
- What happens to the fetus?
- What happens to the mother?
- premature separation of the placenta prior to delivery
- retroplacental blood clot
- blood supply of O2 and nutrients to the fetus is compromised to a greater degree with increasing size of the abruption; potential fetal death
- painful bleeding, hemorrhage
Retained Placental Tissue
- Define
- May cause what?
- retention of tissue after spontaneous miscarriage or elective abortion
- post-partum hemorrhage, infection,
Preeclampsia- Eclampsia
- Define
- Can also cause…
- Who gets it? When?
- Which pregnancy is it most common in?
- systemic syndrome characterized by widespread maternal endothelial dysfunction presenting clinically with hypertension, edema, and proteinuria during pregnancy
- fetus problems due to insufficient blood supply to developing fetus
- 3-5% of pregnancies; 3rd trimester;
- 1st pregnancy, those w/ underlying HTN or diabetes
Preeclampsia- Eclampsia: Pathogenesis
- How do we know that the placenta plays a role in symptoms?
- Theories of pathogenesis (3)
- symptoms disappear after delivery of placenta
- abnormal placental vasculature;
endothelial dysfunction and imbalance of angiogenic and anti-angiogenic factors (more anti-angiogenic factors);
Coagulation abnormalities (imbalance btwn thromboxane and prostacyclin- abnormally high thromboxane)
Preeclampsia- Eclampsia
1. What happens to spiral arteries?
- They fail to remodel; usually, the musculature around them regresses allowing them to be high capacitance vessels;
when this fails to occur, blood vessels can’t carry as much blood to the fetus
Preeclampsia- Eclampsia: How are the following organs involved?
- Liver
- Kidney
- Brain
- Other organs involved
- fibrin thrombi, hemorrhage, necrosis
- fibrin in glomeruli and capillaries, renal cortical necrosis
- hemorrhage and thrombosis
- heart and anterior pituitary
Placenta Morphology in Preeclampsia- Eclampsia
- What happens to placenta?
- What does that cause?
- Malperfusion, ischemia, vascular injury
- –> infarcts, retroplacental hematoma, villous ischemia, acute therosis of uterine vessels (fibrinoid necrosis, macrophages, inflammation)
Distinctions between Preeclampsia and Eclampsia
- What defines Preeclampsia?
- Severe Preeclampsia?
- Eclampsia?
- HELLP Syndrome
- Other complciations (3)
- HTN, edema, proteinuria
- preeclampsia + headache and vision changes
- Preeclampsia + convulsions
- severe preeclampsia + hemolysis, elevated liver enzynes, low platelets
- hypercoaguability, acute renal failure, pulmonary edema
Management of Preeclampsia- Eclampsia
- If baby is at term
- If baby is preterm
- Long term consequences
- deliver
- mild- expectant management; severe- delivery regardless of fetal age
- none for mother;
20% of children develop HTN and microalbuminemia w/in 7 years;
2x increased heart and brain vascular disease
Placental Infections: Ascending
- How common
- How does it get there?
- What causes it?
- Result
- more common
- through birth canal
- usually bacterial,
- premature rupture of membranes, pre-term delivery
Placental Infections: Hematogenous
- How common
- How does it get there?
- What causes it?
- What does it result in?
- less common than ascending
- hematogenous, blood spread
- TORCH infections
- neonate fever, encephalitis, chorioretinitis, hepatosplenomegaly, penumonitis, myocarditis, hemolytic anemia, and vesicular or hemorrhage skin lesions
What are the TORCH infections?
Toxoplasma gondii Others- (parvovirus B19, Syphilis, TB, listeria) Rubella CMV HSV
Gestastional Trophoblastic Disease
- What is it?
- Types (4)
- tumors, proliferation of placental tissue (villous or trophoblastic)
- Hydatiform mole (complete and partial)
Invasive mole
Choriocarcinoma
Placental-site trophoblastic tumor (very rare)
Hydatiform Moles
- What are they?
- How common?
- Who is evaulated?
- Why are they evaluated?
- cystic swelling of chorionic villi with trophoblastic proliferation
- infrequent in US, more common in China or Japan
- most women who rpesent with miscarriage undergo D&C based on Uterus Size (US)/hCG findings
- benign, but want to know and distinguish them with regard to increased risk of invasive mole or choriocarcinoma
Complete Mole
- What happens?
- What happens to villi?
- What can it make?
- what happens to the embryo?
- risk of what?
- 2/3 sperm fertilize an empty ovum
- most villi are enlarged & edematous; diffuse trophoblastic hyperplasia
- androgens
- dies very early, fetal parts rarely seen
- 2.5% risk of choriocarcinoma
Complete Mole
- Gross look
- Close-up Gross look
- Microscopic
- entire placenta, all villi edematous, delicate friable mass of thin-walled, translucent, cystic, grape like structures
- villi look like balloons
- Swollen villi with almost no fetal blood vessels; diffuse cytotrophoblast and syncytial trophoblastic proliferation; marked atypica at implantation
Complete Mole
- Clinical Course
- Diagnostic Test
- What is increased?
- How is it removed?
- What can develop?
- abnormal uterine bleeding, passage of fluid and tissue
- ultrasound (snow storm- larger than expected uterus)
- serum hCG
- curretage,serum hCG levels are followed
- invasive moles (10%), choriocarcinoma (2.5%)
Partial Mole
- What happens?
- What happens to villi?
- Genomes
- Is the fetus present?
- What is risk for choriocarcinoma?
- 2/3 sperm fertilize a normal ovum;
- edematous
- Triploid (69, XXY or 69,XXX) or tetraploid (92, XXXY)
- fetus mostly present, although abnormal
- NOT increased risk
Partial Mole
- Gross look
- Microscopic look
- some villous swelling, lots of solid parts
2. swollen villus, trophoblast proliferation
Invasive Mole
- define
- what can it do to distant sites?
- Presentation
- Risk of what?
- Treatment
- mole that penetrates uterine wall, hydropic chorionic villi invade myometrium
- may embolize, does not disseminate
- vaginal bleeding, persistantly elevated hCG
- uterine rupture
- chemotherapy
Gestational Choriocarcinoma
- Malignant or Benign?
- course
- What cells
- How common?
- What lesions/situations contribute to it?
- Malignant;
- rapidly invasive, widely metastatic; rapidly growing,
- neoplasm of trophoblast derived cells
- uncommon
- 50% from complete moles
25% previous abortion
22% normal pregnancy (intraplacental choriocarcinoma)
Ectopic pregnancy
Choriocarcinoma
- Gross look
- Histo look
- Presentation
- When does it present?
- How advanced is it at the time of presentation?
- necrotic, hemorrhagic, rapidly growing
- proliferation of neoplastic cystotrophoblasts and syncytiotrophoblasts (NO chorionic villi)
- vaginal blood, brown fluid spotting
- during pregnancy, after miscarriage, after curretage, can occur months after
- usually already metastasized
Choriocarcinoma
- What is elevated? When is it not?
- Treatment
- hCG; unless necrotic
2. surgery, chemo (extremely effective); paternal antigens evoke immune response in mothers
Difference between ovarian and gestational choriocarcinoma
- ovarian is result of…
- response to chemo
- what choriocarcinoma is rare?
- extra-embryonic differentiation of malignant germ cells
- ovarian- poorly responsive to chemo, poor prognosis
- testis