5: Antepartum hemorrhage

Question 1

if part of the placental atrophies and is discrete from the rest of the placenta

Answer 1

succenturiate lobe

Question 2

Placenta previa

Answer 2

abnormal implantation of the placenta over the internal cervical os
complete, partial, and marginal

Question 3

vasa previa

Answer 3

Occurs when a velamentous cord insertion causes the fetal vessels to pass over the internal cervical os
Also seen with velamentous and succenturiate placentas

Question 4

placenta accreta, increta, percreta

Answer 4

accreta: superficial attachment of the placenta to the uterine myometrium.
increta: placenta invades the myometrium.
percreta: placenta invades through the myometrium to the uterine serosa. this may lead to invasion of other organs such as the bladder anteriorly or the rectum posteriorly.

Question 5

placenta previa may result in

Answer 5

preterm delivery, PPROM, IUGR, malpresentation, vasa previa, congenital abnormalities, profuse hemorrhage and shock

Question 6

placenta accreta causes inability of placenta to separate properly from uterine wall, can result in

Answer 6

profuse hemorrhage and shock with substantial maternal morbidity and mortality, such as need for hysterectomy, surgical injury to the ureters, bladder, and other viscera, adult respiratory distress syndrome, renal failure, coagulopathy, and death.
EBL is 3,000 to 5,000 mL

Question 7

most frequent indication for a peripartum (during C section) hysterectomy

Answer 7

uterine atony

abnormal placentation is becoming more common

Question 8

major causes of antepartum hemorrhage include

Answer 8

placenta previa (20%) and placental abruption (30%).

Question 9

placenta previa presentation

Answer 9

sudden and profuse PAINLESS vaginal bleeding
the “sentinel” (first) bleed—usually occurs after 28 weeks of gestation
digital exam is CONTRAINDICATED

Question 10

Placenta accreta (and increta) presentation

Answer 10

usually asymptomatic. On rare occasions, however, a patient with a percreta into the bladder or rectum may present with hematuria or rectal bleeding.

Question 11

Circumvallate placenta

Answer 11

Occurs when the membranes double back over the edge of the placenta, forming a dense ring around the periphery of the placenta. Often considered a variant of placental abruption, it is a major cause of second-trimester hemorrhage

Question 12

Velamentous placenta

Answer 12

Occurs when blood vessels insert between the amnion and the chorion, away from the margin of the placenta, leaving the vessels largely unprotected and vulnerable to compression or injury

Question 13

Succenturiate placenta

Answer 13

An extra lobe of the placenta that is implanted at some distance away from the rest of the placenta
Fetal vessels may course between the two lobes, possibly over the cervix, leaving these blood vessels unprotected and at risk for rupture

Question 14

predisposing factors for placenta previa

Answer 14

Prior cesarean section and uterine surgery (e.g., myomectomy) 
Multiparity 
Multiple gestation 
Erythroblastosis 
Smoking 
History of placenta previa 
Increasing maternal age

Question 15

diagnosing placenta previa

Answer 15

transvaginal US»transabdominal US

Question 16

deliver placenta previa pts via C section if ?

Answer 16

placenta edge is less than 2cm from internal os

Question 17

management of placenta previa

Answer 17

strict pelvic rest, modified bed rest

immediate C section if unstoppable labor, fetal distress, and life-threatening hemorrhage

Question 18

70% of patients with placenta previa have a recurring bleeding episode and will require delivery before

Answer 18

36 weeks
if make it to week 36: amniocentesis to determine fetal lung maturity and delivery by c section between 36 and 37 weeks after confirmation of fetal lung maturity. If not mature, elective cesarean at 38 weeks, without repeating the amniocentesis or earlier if bleeding occurs or the patient goes into labor

Question 19

now research shows patients with suspected placenta previa and/or accreta should be delivered between

Answer 19

34 and 37 weeks with minimal benefit gained by confirming fetal lung maturity.

Question 20

course of action in the case of vaginal bleeding and suspected placenta previa and/or placenta accreta:

Answer 20

1. stabilize
2. prepare for hemorrhage: transfusions to maintain HCT >25%
3. prepare for preterm delivery: steroids, tocolytics to prolong pregnancy up to 34 weeks

Question 21

considerations for suspected placenta accreta/increta/percreta:

Answer 21

1. Plan for total abdominal hysterectomy at the time of cesarean section; attempts at detachment causes hemorrhage
2. Schedule delivery at 34 to 37 weeks of gestation
3. Plan ahead and have back-up available.

Question 22

Placental abruption (abruptio placentae)

Answer 22

premature separation of the normally implanted placenta from the uterine wall, resulting in hemorrhage between the uterine wall and the placenta. 50% occur before labor and after 30 weeks, 15% occur during labor, and 30% are identified only on placental inspection after delivery.

Question 23

placental abruption may result in

Answer 23

premature delivery, uterine tetany, disseminated intravascular coagulation (DIC), and hypovolemic shock.

Question 24

Predisposing factors for placenta abruption

Answer 24

*Hypertension* most common, preeclamspsia, 
HTN secondary to Cocaine or Methamphetamine use
Previous placental abruption
Advanced maternal age
Multiparity
Uterine distension
Multiple pregnancy
Polyhydramnios
Vascular deficiency
Diabetes mellitus
Collagen vascular disease
Cigarette smoking
Alcohol use (>14 drinks/wk)
Circumvallate placenta
Short umbilical cord

Question 25

Precipitating factors for placental abruption

Answer 25

Trauma
External/internal version
Motor vehicle accident
Abdominal trauma
Sudden uterine volume loss
Delivery of first twin
Rupture of membranes with polyhydramnios
Preterm premature rupture of membranes

Question 26

mortality from placental abruption

Answer 26

maternal: hemorrhage, cardiac failure, renal failure
fetal: preterm birth, hypoxia resulting from decreased placental surface area and maternal hemorrhage

Question 27

placental abruption presentation

Answer 27

PAINFUL bleeding (vs previa) 
third-trimester vaginal bleeding associated with severe abdominal pain and/or frequent, strong contractions. However, about 30% of placental separations are small with few or no symptoms and are identified only after inspection of the placenta at delivery

Question 28

Couvelaire uterus

Answer 28

a life-threatening condition and occurs when there is enough blood from the abruption that markedly infiltrates the myometrium to reach the serosa, especially at the cornua, that it gives the myometrium a bluish purple tone that can be seen on the surface of the uterus.

Question 29

CANNOT rule out abruption if

Answer 29

negative US findings

Question 30

placental abruption confirmed at delivery with

Answer 30

presence of a retroplacental clot with overlying placental destruction confirms the diagnosis

Question 31

severe placental abruption results in consumptive coagulopathy
levels?

Answer 31

-hypofibrinogenemia (i.e., plasma levels less than 150)

Question 32

mechanism of coagulopathy in abruption

Answer 32

activation of intravascular coagulation with varying degrees of defibrination.
Procoagulants are also consumed in the retroplacental clots
activation of plasminogen to plasmin, which lyses fibrin microemboli to maintain microcirculatory patency
may result in overt thrombocytopenia

Question 33

suspected placental abruption management

Answer 33

1. stabilize the patient:CBC, type and cross, PT/PTT, fibrinogen, and D-dimer or fibrin split products. For an Rh- woman, RhoGAM, prepare for emergent c sx (anesthesia)
2. Prepare for the possibility of future hemorrhage: IVF, blood, FFP, cryoprecipitate
3. Prepare for preterm delivery
4. Deliver if bleeding is life threatening or fetal testing is nonreassuring

Question 34

More than 90% of all uterine ruptures are associated with ?

Answer 34

a prior uterine scar either from cesarean section or other uterine surgery
others: abdominal trauma, L&D probs (i.e. improper oxytocin use, manual pressure), spontaneous (i.e. placenta percreta, multiple gestation, grand multiparity, invasive mole, or choriocarcinoma).

Question 35

Risk Factors for Uterine Rupture

Answer 35

Prior uterine surgery/uterine scar 
Injudicious use of oxytocin 
Grand multiparity 
Marked uterine distension 
Abnormal fetal lie 
Large fetus 
External version 
Trauma

Question 36

presentation of uterine rupture

Answer 36

sudden onset of intense abdominal pain +/- vaginal bleeding.
other signs: nonreassuring fetal testing, abnormal abdominal contour, cessation of uterine contractions, absent FHTs, and regression of the presenting fetal part

Question 37

Management of uterine rupture

Answer 37

immediate laparotomy and delivery, repair rupture site and maintain hemostasis
may require a hysterectomy, discouraged to attempt future pregnancies due to recurrence

Question 38

Most pregnancies complicated by rupture of a fetal vessel are due to ?

Answer 38

velamentous cord insertion, the blood vessels insert between the amnion and chorion away from the placenta instead of inserting directly into the chorionic plate
-may have additional vasa previa

Question 39

complications of vasa previa

Answer 39

fetal exsanguination/death: the fetal blood volume is only about 80 to 100 mL/kg, loss of even small amounts of blood could prove disastrous to the fetus. Additionally, pressure on the unprotected vessels by the presenting fetal part could lead to fetal asphyxia and death.

Question 40

risk factors for fetal vessel rupture

Answer 40

abnormal placentation leading to a succenturiate lobe as well as multiple gestations that increase the risk of velamentous insertion

Question 41

have a high index of suspicion for a ruptured vasa previa if

Answer 41

bleeding accompanies ROM in labor, especially if there are associated FHR decelerations, fetal bradycardia, or a sinusoidal FHR pattern (indicates anemia)

Question 42

Apt test to examine vaginal bleeding

Answer 42

examination of the blood for nucleated (fetal) RBCs
-dilute the blood with water, collecting the supernatant, and combining it with 1% NaOH. If the resulting mixture is pink, it indicates fetal blood; a yellow-brown color is seen with maternal blood

Question 43

treatment of a ruptured fetal vessel

Answer 43

emergent cesarean delivery, elective at 35 weeks if dx in antepartum period
if choose to under go TOLAC, AROM is contraindicated

Question 44

what is the imaging modality of choice to evaluate for the myometrial and/or bladder invasion of the placenta, particularly when it is not clear on ultrasound?

Answer 44

MRI of abdomen/pelvis without contrast