5. Obstetrical Hemorrhage Flashcards
Define: Obstetrical Hemorrhage (1)
vaginal bleeding from 20 wk to term
Name DDX for obstetrical hemorrhage (7)
- bloody show (represents cervical changes/early stages of dilation) – most common etiology in T3
- placenta previa
- abruptio placentae – most common pathological etiology in T3
- vasa previa
- cervical lesion (cervicitis, polyp, ectropion, cervical cancer)
- uterine rupture
- other: bleeding from bowel or bladder, abnormal coagulation
Define: Placenta Previa (1)
Abnormal location of the placenta near, partially, or completely over the internal cervical os
Name etiology and epidemiology: Placenta Previa (2)
- Idiopathic
- 0.5-0.8% of all pregnancies
Name etiology and epidemiology: Abruptio Placentae (2)
- Idiopathic
- 1-2% of all pregnancies
Define: Abruptio Placentae (1)
Premature separation of a normally implanted placenta after 20 wk GA
Name risk factors: Placenta Previa (6)
- History of placenta previa (4-8% recurrence risk)
- Multiparity
- Increased maternal age
- Multiple gestation
- Uterine tumour (e.g. fibroids) or other uterine anomalies
- Uterine scar due to previous abortion, C/S, D&C, myomectomy
Name risk factors: Abruptio Placentae (8)
- Previous abruption (recurrence rate 5-16%)
- Maternal HTN (chronic or gestational HTN in 50% of abruptions) or vascular disease
- Cigarette smoking (>1 pack/d), excessive alcohol consumption, cocaine
- Multiparity and/or maternal age >35 yr
- preterm premature rupture of membranes (PPROM)
- Rapid decompression of a distended uterus (polyhydramnios, multiple gestation)
- Uterine anomaly, fibroids
- Trauma (e.g. motor vehicle collision, maternal battery)
Differentiate bleeding of Placenta Previa and Abruptio Placentae (2)
- Placenta Previa: Painless
- Abruptio Placentae: Usually painful
Define: Placenta Previa (2)
- placenta implanted in the lower segment of the uterus, presenting ahead of the leading pole of the fetus
- placental position is described in relation to the internal os as “mm away” or “mm of overlap”
Name clinical features: Placenta Previa (7)
- PAINLESS bright red vaginal bleeding (recurrent), may be minimized and cease spontaneously but can become catastrophic
- mean onset of bleeding is 30 wk GA, but onset depends on degree of previa
- physical exam
- do not perform digital vaginal exam until ruling out placenta previa
- uterus soft and non-tender
- presenting fetal part high or displaced
- FHR usually normal
- shock/anemia correspond to degree of apparent blood loss
Name FETAL complications: Placenta Previa (6)
- perinatal mortality low but still higher than with a normal pregnancy
- prematurity (bleeding often dictates early C/S)
- intrauterine hypoxia (acute or intrauterine growth restriction IUGR)
- fetal malpresentation
- preterm premature rupture of membranes (PPROM)
- risk of fetal blood loss from placenta, especially if incised during C/S
Name FETAL complications: Placenta Previa (6)
Name MATERNAL complications: Placenta Previa (4)
- <1% maternal mortality
- hemorrhage and hypovolemic shock, anemia, acute renal failure, and pituitary necrosis (Sheehan syndrome)
- placenta accreta – especially if previous uterine surgery or anterior placenta previa
- hysterectomy
Name investigations: Placenta Previa (3)
- transvaginal U/S is more accurate than transabdominal U/S at diagnosing placenta previa at any gestational age
- spontaneously resolution is likely with increasing uterine distention if the placenta obscures the internal os by less than 20 mm at 20 wk GA
- transvaginal U/S should be repeated in the T3 as continued change in the placental location is likely
Name goal of management of: Placenta Previa (1)
- keep pregnancy intrauterine until the risk of continuing pregnancy outweighs the risk of preterm delivery
Describe the management of Placenta Previa (8)
-
stabilize and monitor
- maternal stabilization: large bore IV with hydration, O2 for hypotensive patients
- maternal monitoring: vitals, urine output, blood loss, blood work (hematocrit, CBC, INR/PTT, platelets, fibrinogen, FDP, type and cross match)
- electronic fetal monitoring
- U/S assessment: when fetal and maternal conditions permit, determine fetal viability, GA, and placental position
- Rhogam® if mother is Rh negative
- Kleihauer-Betke test to determine extent of fetomaternal transfusion and administer Rhogam® at adequate dose
-
GA <37 wk and minimal bleeding: expectant management
- admit to hospital
- limited physical activity, no douches, enemas, or sexual intercourse
- consider corticosteroids for fetal lung maturity
- delivery when fetus is mature or hemorrhage indicating maternal or fetal compromise
- GA ≥37 wk – deliver by C/S
When to perferm vaginal exam for placenta previa? (1)
Do NOT perform a vaginal exam until placenta previa has been ruled out by U/S
Define: Abruptio Placentae (2)
- partial or total placental detachment that is premature and caused by bleeding at the decidual-placental interface
- occurring >20 wk gestation
Describe classification: Abruptio Placentae (4)
- total (fetal death inevitable) vs. partial
- external/revealed/apparent: blood dissects downward toward cervix
- internal/concealed/occult (20%): blood dissects upward toward fetus, may or may not present with vaginal bleeding
- most are mixed
Describe presentation: Abruptio Placentae (4)
- usually PAINFUL (80%) vaginal bleeding (bleeding not always present if abruption is concealed), uterine tenderness, uterine contractions/hypertonus
- pain: sudden onset, constant, localized to lower back and uterus
- shock/anemia out of proportion to apparent blood loss
- ± fetal distress, fetal demise (15% present with demise), bloody amniotic fluid (fetal presentation typically normal)
- ± coagulopathy
Name complications: Abruptio Placentae (10)
-
fetal complications:
- perinatal mortality 25-60%
- prematurity
- intrauterine hypoxia
-
maternal complications:
- <1% maternal mortality
- disseminated intravascular coagulation DIC (in 20% of abruptions)
- acute renal failure
- anemia
- hemorrhagic shock
- pituitary necrosis (Sheehan syndrome)
- amniotic fluid embolus
Name investigations: Abruptio Placentae (1)
clinical diagnosis, U/S not sensitive for diagnosing abruption (sensitivity = 15%)
Describe management: Abruptio Placentae (7)
- maternal stabilization: large bore IV with hydration, O2 for hypotensive patients
- maternal monitoring: vitals, urine output, blood loss, blood work (hematocrit, CBC, PTT/PT, platelets, fibrinogen, FDP, type and cross match)
- electronic fetal monitoring
- blood products on hand (red cells, platelets, cryoprecipitate) because of DIC risk
- Rhogam® if Rh negative
- Kleihauer-Betke test may confirm abruption
- abruption without fetal/maternal compromise (mild abruption)
- GA <37 wk: use serial Hct to assess concealed bleeding, deliver when fetus is mature or when hemorrhage dictates
- GA ≥37 wk: stabilize and deliver
- abruption with fetal/maternal compromise (moderate to severe abruption)
- hydrate and restore blood loss and correct coagulation defect if present
- vaginal delivery if no contraindication and no evidence of fetal or maternal distress
- C/S if live fetus and fetal or maternal distress develops with fluid/blood replacement, labour fails to progress, or if vaginal delivery otherwise contraindicated
Name the most common cause of disseminated intravascular coagulation (DIC) in pregnancy (1)
Abruptio placentae
Describe: Kleihauer-Betke Test (1)
Quantifies fetal cells in the maternal circulation
Define: Vasa Previa (2)
- unprotected fetal vessels pass over the cervical os
- associated with velamentous insertion of cord into membranes of placenta or succenturiate (accessory) lobe
Describe epidemiology: Vasa Previa (1)
- 1 in 5000 deliveries – higher in twin pregnancies
Describe clinical features: Vasa Previa (3)
- PAINLESS vaginal bleeding and fetal distress (tachy-to-bradyarrhythmia in a sinusoidal pattern)
- if undiagnosed, 50% perinatal mortality, increasing to 75% if membranes rupture (most infants die of exsanguination)
- if diagnosed antenatally on U/S without labour or symptoms, then 97% survival
Describe investigations: Vasa Previa (2)
- Apt test (NaOH mixed with the blood) can be done immediately to determine if the source of bleeding is fetal (supernatant turns pink) or maternal (supernatant turns yellow)
- Wright’s stain on blood smear and look for nucleated red blood cells (in cord, not maternal blood)
Describe management: Vasa Previa (2)
- planned C/S (35-36 weeks)
- or if bleeding, emergency C/S (since bleeding is from fetus, a small amount of blood loss can have catastrophic consequences)
Name Obstetrical Complications (7)
- Preterm Labour
- Premature Rupture of Membranes
- Postterm Pregnancy
- Intrauterine Fetal Demise
- Intrauterine Growth Restriction
- Macrosomia
- Polyhydramnios/Oligohydramnios
