Obstetric Pathology 2 Flashcards
(44 cards)
Define pre-eclampsia.
Complication of pregnancy, a systemic syndrome of maternal endothelial dysfunction causing hypertension, proteinuria, and edema.
How common is pre-eclampsia?
It is increasingly common, occurring
in 7.5% of pregnancies, usually in the
third trimester.
What are risk factors for pre-eclampsia?
First pregnancy Age less than 20 or over 40 Obesity Diabetes mellitus Hypertension New paternity Previous pre-eclampsia Multiple pregnancies Long interval between pregnancies
Pathogenesis of pre-eclampsia
Normally, trophoblast cells invade myometrial spiral arteries going to the placenta, destroy the smooth muscle cells in their walls and convert them from small caliber resistance vessels to large caliber capacitance vessels that accommodate vastly increased blood flow later in gestation. Pre-eclamptic trophoblast fail to thus convert spiral arteries, resulting in placental ischemia
Ischemic placenta releases what anti-angiogenic substances? What does this do?
(1) soluble fms-like tyrosine kinase 1
(sFlt-1), a truncated form of VEGF
receptor that acts as a decoy
(2) soluble endoglin, a form of TGF-beta
receptor that acts as a decoy
blocks VEGF and TGF mediated
production of nitric oxide and prosta-
cyclin, causing maternal hypertension,
proteinuria and edema.Ischemic placenta also releases proinflammatory cytokines like ____.
TNF
Pre-ecmalpsia is a ____ state partly due to blockage of prostacyclin production.
procoag
What are some of the deleterious effects of pre-eclampsia on placenta, baby, and momma?
including fetal intrauterine growth
restriction (IUGR), maternal disseminated intravascular coagulation, maternal HELLP syndrome (Hemolysis, Elevated Liver enzymes and Low Platelets) and eclampsia (cerebral edema and seizures).
T or F. Pre-eclampsia and eclampsia are associated with visible changes in
placental arteries very similar to atherosclerosis (a universal disease
of arterial endothelial injury in all permanent organs).
T
Histological changes of uterine blood vessels in eclampsia?
acute atherosis with fibrinoid necrosis/ leakage of plasma, subendothelial macrophages
What is the effect of ischemia on chorionic villi?
The initial effect of ischemia on the development of chorionic villi is accelerated
maturation that makes them more efficient at gas exchange, nutrient import
and waste export, but when ischemia becomes more severe, it results in
villous hypoplasia.
How does necrosis of villi result from pre-eclampsia?
Sluggish blood flow in the intervillous space
and the procoagulant state of pre-eclampsia can lead to fibrin clot formation in the intervillous space, which can lead to necrosis of villi, “choked off” by the clot around them.
How is diagnosis of pre-eclampsia made? What is the treatment and prognosis?
Diagnosis: new onset of hypertension
& proteinuria after 20 weeks gestation
Treatment depends on whether it is mild or severe. Mild: “expectant management” (including steroids to accelerate fetal lung development) Severe: delivery
Prognosis: wide spectrum
What is HELLP syndrome?
(hemolysis, elevated
liver enzymes and low platelets)
= a complication of pre-eclampsia in
4-12% of patients with pre-eclampsia
Pathogenesis of HELLP syndrome
activation of platelets and clotting factors, creating fibrin red cell shredders in capillaries that causes hemolysis, platelet aggregation lowering the count, and thrombi in liver sinusoids that injure hepatocytes, who release their enzymes
What happens to the liver in HELLP syndrome
Liver injury can progress to necrosis,
hemorrhage, even liver rupture.
Complications of HELLP syndrome
20% of patients with HELLP syndrome get disseminated intravascular coagulation;
some get hepato- renal failure,some pulmonary edema and acute respiratory distress
syndrome (ARDS),and 1% die of it.
Causes of placental ischemia and infarction
Pre-eclampsia is the overwhelmingly most common cause, but hyper- coagulable states, autoimmune vasculitis and smoking are also causes of it.
The fetus can tolerate infarction of _____ of the placenta, but extensive infarction causes IUGR, neurological injury, and fetal demise.
more than 50%
What does heavy prenatal drinking do to childhood brain development?
disrupts proper brain development in children and adolescents years after they were exposed to alcohol in the womb.decreased brain plasticity – the brain’s ability to grow and remodel itself based on experience with the outside world. Such adaptation continues throughout one’s life and is crucial to learning new skills and adapting to the environment.
Describe invasive mole and choriocarcinoma
there is a spectrum from non-invasive moles through invasive moles to choriocarcinomas. 7% of partial moles persist after therapy and none become carcinoma. 20% of complete moles persist after initial therapy and 2% become choriocarcinomas. Invasive moles look like well differentiated choriocarcinomas, but do not metastasize
How common is choriocarcinoma?
rare- 1/30,000 pregnancies
Spread of choriocarcinoma
Spreads hematogenously
(like a sarcoma), so to lungs first
Most common first symptom of choriocarcinoma
uterine bleeding
