Placenta Problems Flashcards
what is the amnion?
innermost lining of sac around fetus
what is the chorion?
outermost lining of sac around fetus
what is the decidua?
endometrium of the pregnant uterus
what is the placenta?
extr-embryonic fetal tissue that allows for nutrient and gas exchange
what is the chorionic villus?
placental structure where nutrient and gas exchange actually occurs
what forms the chorionic villi?
villous trophoblast
what forms the non villous parts of the placenta?
extravillous trophoblast
mature placental villi have what linings?
external syncytiotrophoblast lining and internal cytotrophoblast lining
villous blood vessels hold what type of blood?
fetal blood
maternal blood is where in placenta?
intervillous spaces
what are the three blood vessels in the UC?
two umbilical arteries and an umbilical vein
dizygotic twins always have what type of placenta?
dichorionic diamniotic
what are risk factors for multiple gestations
fertility drugs
advanced maternal age
what is twin twin transfusion syndrome?
unbalanced blod flow in anastomotic vessels within the shared placenta…blood transfer from donor to recipient twin
what does recipient twin have in twin transfusion syndrome?
polycythemia, polyhydramnios
what does donor twin have in twin transfusion syndrome?
anemia
growth retardation
oligohydramnios
what type of twin pregnancy has risk of twin transfusion syndrome?
monochorionic
what is placental infection called?
acute chorioamnionitis
what is pathogenesis of acute chorioamnionitis ?
ascending infection from lower gyn tract
what is not involved in acute chorioamnionitis ?
chorionic villi
what organisms often cause acute chorioamnionitis ?
GBS, gram negative enteric flora, anaerobes
what are sx of acute chorioamnionitis ?
maternal fever, uterine tenderness, tachycardia and foul amniotic fluid
how do fetal membranes apper in acute chorioamnionitis ?
cloudy, opaque and yellow
what is placental abruption?
premature separation of placenta from the decidua…prior to delivery
what are sx of placental abruption?
pain, uterine bleeding and contractions
what can happen to fetus in placental abruption?
fetal distress and hypoxia
what is placental previa?
placenta that overlies or is proximate to the internal os of the cervix
what is increased risk with placental previa?
massive blood loss
what usually occurs with placental previa? when?
hemorrhage around 32-34 weeks
does placenta previa hurt?
NO
what are some risk factors for placental abruption?
smoking, cocaine, HTN
what is vasa previa?
when fetall vessel travel in the membrane that covers the cervix rather than in the UC
what can happen to fetal vessels in vasa previa?
they can rupture and get catastrophe
what is placenta accreta?
placenta morbidly aadherant to the uterine wall
what is pathogenesis of placenta accreta?
deficiency of maternal decidua at implantation resulting in abnormal placental attachment to myometrium
what is vasa previa a common cause of?
3rd trimester bleeding
what can happen in placenta accreta that is big risk?
post partum hemorrhage
what is retained in placenta acreta?
placenta
name three subtypes of placenta accreta
accreta adheres
increta invades
perceta perforated
