Spring 2024 OB/GYN Ch 20

• size of an enlarged placenta?

  >5 cm
• weight of an enlarged placenta?

  >600 g
• list some causes for an enlarged placenta

  gestational diabetes

  maternal anemia

  fetal malformation

  congenital neoplasm

  twin to twin transfusion syndrome
• size of a small placenta?

  <1.5 cm
• list some causes for a small placenta

  IUGR

  preeclampsia

  polyhydramnios

  intrauterine infection
• what causes placenta previa?

  when the blastocyst attaches too low in the uterus
• what's the main symptom for placenta previa?

  painless vaginal bleeding in the 3rd trimester
• know the dif -------

  okuurrr

  A) complete

  B) partial

  C) marginal

  D) low lying

  
• what are some factors associated w/ placenta previa?

  advanced maternal age

  cocaine abuse

  prior placenta previa

  multiparity
• what are some complications w/ placenta previa?

  preterm delivery

  maternal hemorrhage

  IUGR

  increased risk of placental invasion
• what's placenta migration?

  used to describe how the placenta changes position within uterine cavity
• when is the placenta considered low lying?

  when the edge of the placenta is <2 cm away from the cervix
• what's placental invasion?

  a condition where the placenta grows too deeply into the uterine wall, sometimes extending into or beyond the muscle layer of the uterus
• what imaging method may be useful in cases of suspected placental invasion to a certain extent of invasion into the myometrium?

  MRI
• correctly label :-{D

  A) accreta

  B) increta

  C) percreta

  
• placenta invasion is associated with:

  placenta previa

  previous c section (it allows trophoblastic invasion)
• sono findings of placenta invasion:

  Blood vessels behind the placenta (basal plate) might not look normally hypoechoic

  Focal basal plate thinning (accreta)

  Increased myometrial thickness and echogenicity (increta)

  Focal myometrial bulge (percreta)
• what does this sonogram display?

  retroplacental vascular complex

  
• what's placental hemorrhage?

  refers to bleeding from placenta from any cause
• which is more common: placental abruption or placental hemorrhage?

  placental hemorrhage
• where can placental hemorrhage occur?

  retroplacental

  intraplacental

  subchoriotic

  subamniotic
• acute bleed = echogenic
• subacute and chronic bleed = more hypoechoic
• what's placental abruption?

  when the placenta detaches from uterine wall before labor
• placental abruption occurs in 1 in 120 pregnancies
• list some risk factors for placental abruption:

  maternal HTN

  AMA

  cocaine use

  fibroids
• list the symptoms associated w/ placental abruption:

  abdominal pain

  may or may not have vaginal bleeding depending on the location ofthe abruption
• list the two types of placental abruption:

  concealed

  external
• concealed abruption = hemorrhage is confined to uterine cavity
• external abruption = blood drains through the cervical os and results in painful vaginal bleeding
• which type of placental abruption may have complete placental detachment?

  concealed abruption
• which type of placental abruption would make it sonographically difficult to diagnose if no blood remains in the retroplacental space?

  external abruption
• label the following w/ the correct term:

  :-{D

  A) concealed

  B) external

  C) complete detachment

  
• clinical history is key when determining placental abruption
• sono findings of placental abruption:

  placenta is lifted off the uterine wall

  retroplacental fluid collection of different echogenicity (likely hypo)

  placental may look normal/thickened (thicker may be clot w/ no color)
• placental abruption prognosis depends on:

  degree of placental abruption

  gestational age

  *may cause intrauterine hypoxia (reduce oxygen to fetus)
• name the path:

  placental abruption

  
• what's the most common type of abruption?

  marginal abruption aka subchorionic bleed
• with marginal abruption, how does the bleeding occur?

  when tiny veins at the edge of the placenta tear, causing a bleed with lower pressure
• where does marginal abruption occur?

  it starts from the edge of the placenta, goes under the placental membranes, and usually involves only a small part of the placenta detaching