placenta Flashcards
Placenta abruption - definition? result?
premature seperation of the placenta from the uterus
–> tearing of the placental blood vessels and hemorrhaging into the separated space
Placenta abruption - this can occur … (when)
before / during / after labor
Placenta abruption - complications
- if large separation with life threatening bleeding –> premature delivery, uterine tetany, DIC, hypovolemic shock (and sheehan syndrome), fetal distress (death or hypoxia)
- small separation –> no clinical signs and symptoms
Placenta abruption - etiology and precipitating factors
unknown etiology. Factors:
- maternal hypertension (chronic, preeclampsia, eclampsia) 2. Prior placental abruption 3. cocaine
- external trauma 5. smoking during pregnancy
Placenta abruption - diagnostic test
Clinically
U/S (not required) to distinguish from previa
types of placental abruption
- concealed –> blood within uterine cavity (+ SERIOUS COMPLICATIONS)
- external –> blood drains through cervix
Placenta abruption - indications for cesarean delivery
- uncontrollable maternal hemorrhage
- rapidly expanding concealed hemorrhage
- fetal distress
- rapid placental separation
placental abruption - vaginal delivery indications
- placental separation is limited
- fetal heart tracing is assuring
- separation is extensive and fetus is dead
placenta abruption - clinical presentation
sudden onset vaginal blededing (80%) abd or back pain high frequency, low intensity contractions hypertonic, DISTENDED, tender uterus fetal HR abnormalities
Placenta previa - definition
abnormal implantation of the placenta over the internal cerival os (3rd TRIMESTER) –> the cause of 20% of all prenatal hemorrhages
Risk factors for placenta previa
- previous cesarean deliveries
- previous uterine surgery
- multiple gestations
- previous placenta previa
pregnant woman in third trimester present with vaginal bleeding - next step?
transbdominal US
no digital vaginal exam before –> it may lead to separation between placenta + uterus resulting in severe hemorrhage
placenta previa presentation
painless vaginal bleeding after 20 weeks
placenta previa - diagnostic tests
tranabdominal followed by transvaginal sonogram
placenta previa - types
US identifies the types:
- complete: complete covering the internal cervix os
- partial: partial covering
- marginal: often touching the os
- vasa previa: fetal vessel over the os
- low lying: implanted in the lower segment of the uterus but NOT covering (more than o cm but less than 2 away
low lying placenta?
placenta that is implanted in the lower segment of the uterus but NOT covering the internal cervical os (more than o cm but less than 2 away)
placenta previa - treatment / magement
- treatment is done when there is large bleeding or drop of Hct. (consists of strict pelvic rest + nothing + intercourse).
- There are several indications for immediate cesarean delivering
- prepare for life threatening bleeding (type + screen blood, CBC, PT)
- if preterm –> prepared with betamethasone
- c- section at 36-37 wks
indications for immediate cesarean delivering in placenta previa
- Unstoppable labor (cervix dilated more than 4 cm)
- severe hemorrhage
- fetal distress
Placenta abruption vs previa (according to diagnosis)
previa –> painless vaginal bleeding
abruption –> painful vaginal bleeding
vasa previa - mechanism
fetal vessels transverse the internal cervical os and are vulnerable to injury during amniotomy
vasa previa - presentation
painless vaginal bleeding and feta HR abnormalities AFTER amniotomy
Vasa previa - management
emergency C-section
Vasa previa is frequently associated with
velamentous umbilical insertion
velamentous umbilical insertion?
cord inserts in chorioamniotic membrane rather than placenta –> fetal vessels travel to placenta unprotected by Wharton jelly
placenta invasion - types
abn adheres to the superficial uterine wallincreta attaches to myometriumpercreta_ invades into uterine serosa, bladder wall, or rectal wall
placenta invasion - presentation / treatment
patients are usually asymptomatic, unless invasion into the bladder or rectum results in hematuria or rectal bleeding . Haemorrhage and shock if placenta cannot detach after delivery –> often hysterectomy
