Clin: Obstetric Hemorrhage and Puerperal Sepsis - Moulton Flashcards
what labs should be drawn on initial evaluation of antepartum hemorrhage?
- CBC and coagulation profile
- serial Hgb/Hct
- blood type and crossmatch for 4 units of blood (packed RBC)
1 unit (250-300cc) will raise the Hct/Hgb by how much?
Hct: 3%
Hgb by 1g/dL
always avoid a digital exam until what has been ruled out by US?
placenta previa
- do a sterile speculum exam instead
what are the most common reasons for vaginal bleeding BEFORE 20 weeks?
- abortion
- ectopics
- cervical/vaginal etiology (cancer, trauma, polyps)
- cervical insufficiency
what are the most common reasons for vaginal bleeding AFTER 20 weeks (upper genital tract)?
- placental abruption
- placenta previa
- uterine rupture
- vasa previa (placental blood vessels near cervical opening)
what are the most common reasons for vaginal bleeding AFTER 20 weeks (LOWER genital tract)?
- “bloody show” labor
- cervical polyps
- infections
- trauma
- cancer
- vulvar varicosities
- blood dyscrasia
implantation of the placenta over the cervical os
- most common type of abnormal placentation
- 1 in 200 pregnancies
- accounts for 20% of all cases of antepartum hemorrhage
- presents classically as PAINLESS vaginal bleeding (75% of the time, 20% will have associated contractions)
placenta previa
what are the risk factors for placenta previa?
- maternal age >35
- multiparity
- multiple gestations
- cocaine and smoking
- prior previa (up to 8% risk of previa in subsequent pregnancy)
- previous c-section
characterized by the edge of the placenta extending to the margin of the cervical os
- does NOT cover the os
marginal placenta previa
partial occlusion of the cervical os by the placenta
partial placenta previa
cervical os is completely covered by the placenta
- most serious type, is associated with greater blood loss
complete placenta previa
how is placenta previa diagnosed?
almost completely by US
- 4-5% of patients will have some degree of previa at 24 weeks gestation
- repeat US at 30 weeks -> 90% will resolve by 32-35 weeks (known as placental migration)
which type of previa is the least likely to resolve?
complete
- only 10% of cases resolve by third trimester
what is the management of placenta previa?
- if bleeding not profuse, pt is managed in hospital on bed rest, may send home if stable and bleeding stops 970% of patients will have recurrent bleeding)
- deliver via c-section at 36-37 weeks with documented fetal lung maturity
how do you prepare for serial blood draws?
- serial blood draws
- NPO status
- type and cross 4 units of blood
what is the Kleihauer-Betke test?
blood test to determine the amount of fetal Hgb transferred from the fetus to the mom’s bloodstream
- give Rhogam if indicated (Rh negative)
what should you also give if prior to 34 weeks to prepare for preterm delivery?
betamethasome (antenatal steroids)
- tocolysis can be used in stable patients
abnormal firm attachment to the superficial lining of the myometrium
- most common
placenta ACCRETA
when the placenta invades the myometrium
placenta INCRETA
when the placenta invades through the myometrium into the uterine serosa
- least common
placenta PERCRETA
what are the risk factors for placenta accreta?
- 1 previous c-sections and previa (incidence of accreta is 25%)
- multiple c-sections and previa (incidence of accreta is 65%)
premature separation of the normally implanted placenta
- 1 in 150 live births
- the most common cause of third trimester bleeding
- accounts for 30% of all cases of antepartum hemorrhage
- presents as PAINFUL bleeding, uterine tenderness, uterine hyperactivity, fetal distress and/or death
placental abruption (abrupto placenta)