Placenta previa
Complete, partial, marginal
Most common reasons for peripartum hysterectomy?
Uterine atony FORMERLY, now it’s placenta previa w/ associated accreta (2/3 of them need hysterectomy)
Placenta increta
Placenta invades myometrium
Placenta percreta
Placenta invades thru myometrium INTO the serosa…or even beyond!
Differential of antepartum bleeding?
- Placenta previa, placental abruption, vasa previa
- Uterine rupture
- Fetal vessel rupture
BLEEDING USUALLY FRANK
Placenta accreta
Adheres to the UTERINE WALL.
Velamentous placenta
When blood vessels insert between the amnion and chorion. Vessels largely unprotected and vulnerable to compression or injury.
Placenta previa epidemiology
0.5% of pregnancies
20% of all antepartum hemorrhage
Placenta previa w/ accreta incidence?
5% of placenta pre via cases
Rules about placenta previa?
1) The later in pregnancy its diagnosed, the higher the likelihood of persistence to delivery
2) Low-lying placenta in 2nd trimester is a risk factor for developing VASA PREVIA…use u/s to check later in pregnancy
Predisposing factors for placenta previa?
1) History of placenta previa
2) Prior uterine scar (eg. prior c/s), prior uterine surgery eg. myometctomy
- Multiparity
- Multiple gestation
- Erythroblastosis
- Smoking
- Increasing maternal age
- Uterine anomaly
Diagnosis of placenta previa?
ULTRASOUND
Transvaginal is better bc of fewer false positives. It’s not dangerous with its placement.
Treatment of placenta previa?
Strict pelvic rest (no sex) and modified bed rest.
Some hospitalize right away.
Others, no hospitalized bed rest until large bleed, or drop in Hct of > 3 points.
When should you DELIVER NO MATTER GESTATIONAL AGE?
- Unstoppable labor
- Fetal distress
- Life-threatening hemorrhage
Which placenta abnormality patients should get c/s? Vaginal considered for which?
C/S= PLACENTA 2 cm from os)
Recent decision regarding planning delivery in placenta previa?
34 up until 37 at the latest is probably optimal AND amnio isn’t that useful for determining fetal lung maturity
What do you need to do with ACUTE SETTING of vaginal bleeding and suspected previa or accreta?
1) Stabilize patient- IV catheters, labs of HCT, type cross, RhoGAM after a Kleihaur-Betke test
2) Prepare for catastrophic hemorrhage- transfusions are usually given to maintain Hct of 25% or more
3) Prepare for preterm delivery- give steroids; be cautious with tocolytics
Plan when you’re dealing with known placenta previa or accreta?
1) Plan for TAH at the time of cesarean (esp with accreta)
2) Schedule delivery for 34-37 wks
3) Plan ahead and have backup available like blood products
Placental abruption definition
Premature separation of normally implanted placenta from the uterine wall. Hemorrhage between wall and placenta.
Concealed vs. external hemorrhage?
20% concealed
80% frank bleeding on outside of body
Predisposing factors to placental abruption?
-Hypertension #1 (whether chronic, preeclampsia, or cocaine/methamphetamine induced)
- Previous one
- Advanced maternal age
- Multiparity
- Uterine distension
- Multiple pregancy
- Polyhydramnios
- Vascular deficiency
- Diabetes
- Collagen vascular disease
- Cocaine or methamphetamine use
- Cigarette smoking
- Alcohol use
- Circumvallate placenta
- Short umbilical cord
Precipitating factors for placental abruption?
- Trauma
- External/internal version
- MVA, abdominal trauma
- Sudden uterine volume loss (eg. delivery of first twin)
- Rupture of membranes with polyhydraminos
- PPROM
Epidemiology of placental abruption
0.5-1.5% of pregnancies
Incidence increases with number of gestations but the MORTALITY is greatest among SINGLETONS!
Classic presentation of placental abruption?
Third trimester vaginal bleeding associated with severe abdominal pain and/or frequent strong contractions
THOUGH MANY HAVE FEW OR NO SYMPTOMS and are id’d after seeing the placenta after delivery
