ch 5 antepartum hemorrhage

Question 1

3rd trimester bleeding occurs in 4-5% of pregnancies, may be obstetric or nonobstetric..

Answer 1

obstetric cause:
placenta - placenta previa, placental abruption, vasa previa
maternal - uterine rupture
fetal - fetal vessel rupture

nonobstetric:
cervical - severe cervicitis, polyps,k cervical dysplasia/cancer
vaginal/vulvar - lacerations, varices, cancer
other - hemorrhoids, congenital bleeding disorder, abdominal / pelvic trauma, hematuria

Question 2

placenta previa - abnormal implantation of placenta over interna cervical os

Answer 2

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Question 3

uterine scarring may predispose placental implantation in lower uterine segment

Answer 3

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Question 4

90% of low lying placentas identified early in pregnancy will appear to move away from cervix and out of lower uterine segment

Answer 4

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Question 5

placenta accreta

Answer 5

condition in which placenta invades into and is inseparable from the uterine wall. when invasion extends into myometrium, this is termed placenta INCRETA.

when invasion is through myometrium and serosa - PLACENTA PERCRETA.

Question 6

placenta accreta causes inability of placenta to properly separate from uterine wall after delivery of fetus - resulting in profuse hemorrhage and shock with substantial maternal morbidity and mortality , such as need for hysterectomy, surgical injury to ureters, bladder, and other viscera, adult respiratory distress syndrome, renal failure, coagulopathy, and death.

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Question 7

2/3 of women with placenta previa and associated accreta require a hysterectomy at the time of delivery

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Question 8

vasa previa - when velamentous cord insertion causes fetal vessels to pass over internal cervical os.

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Question 9

velamentous placenta occurs when blood vessels insert between amnion and chorion , away from margin of placenta, leaving vessels largely unprotected and vulnerable to compression / injury

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Question 10

marginal or low lying placenta diagnosed when placental edge is < 2cm from , but not covering internal os.

Answer 10

< 2cm

Question 11

patients with placenta previa classically present with sudden and profuse

Answer 11

PAINLESS VAGINAL BLEEDING.
usually after 28 weeks of gestation.

placenta accreta (and increta) usually asymptomatic

Question 12

vaginal exam is contraindicated in placenta previa because digital exam can cause further separation of placenta and trigger catastrophic hemorrhage

Answer 12

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Question 13

optimal distance for visuualization of the cervix is 2-3 cm away from the cervix, so probe is generally not advanced sufficiently to make contact with the placenta

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Question 14

placenta accreta should be suspected in women who have both placenta previa and a history of cesarean delivery

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Question 15

unstoppable labor, fetal distress, and life threatening hemorrhage are all indications for immediate cesarean deliveyr regardless of gestational age.

Answer 15

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Question 16

predisposing and precipitating factors for placental abruption:

Answer 16

maternal hypertension, prior hx of placental abruption, maternal cocaine use, tobacco use, external maternal trauma, rapid decompression of overdistended uterus.

Question 17

in cases of abruptions that are severe enough to cause fetal death, 50% due to HTN, 25% from chronic HTN, and 25% from preeclampsia

Answer 17

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Question 18

classic presentation of placental abruption is
3rd trimester vaginal bleeding associated with severe abdominal pain and/or frequent, strong contractions.

however, 30% of placental separations are small with few/ no symptoms and are identified only after inspection of placenta at delivery.

Answer 18

classic presentation of placental abruption is

3rd trimester vaginal bleeding associated with severe abdominal pain and/or frequent, strong contractions.

Question 19

presentation of abruptio placentae
symptom: vaginal bleeding - 80%
uterine tenderness/abdominal / back pain - 67%
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Question 20

physical exam: patient with placental abruption will often have vaginal bleeding and a firm, tender uterus. on fetal heart monitoring, nonreassuring fetal heart tracing is frequently seen secondary to hypoxia.

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Question 21

presence of retroplacental clot with overlying placental destruction confirms diagnosis

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Question 22

more than 90% of all uterine ruptures are associated with prior uterine scar either from cesarean section or other uterine surgery

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Question 23

presentation of uterine rupture: intense abdominal pain

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Question 24

most pregnancies complicated by rupture of a fetal vessel are due to VELAMENTOUS CORD INSERTION where blood vessels insert between amnion and chorion away from placenta instead of inserting directly into chorionic plate.
because the vessels course unprotected through membranes before inserting on placental margin, they are vulnerable to rupture, shearing, or laceration.

Answer 24

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Question 25

if patients placenta previa persists into third trimester, then she is most at risk for placenta accreta in the presence of an anterior placenta previa and a history of two cesarean sections

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Question 26

more than 90% of low lying placentas will appear to move away from cervix and out of lower uterine segment.

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Question 27

placenta previa occurs in as many as 1-4% of women with prior cesarean section

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Question 28

if placenta previa persists,it can be complicated by an asscoated placenta accreta in approximately 5% of cases.

Answer 28

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Question 29

because patient has had cs x2, has anterior placenta previa, and because sonographer cannot distinguish placenta from the bladder, might be helpful to get further imaging to rule out placenta accreta, increta, or percreta.

Answer 29

MRI is imaging modality to evaluate for myometrial and/or bladder invasion of the placenta,

Question 30

there is an increase incidence of VASA PREVIA when there is a SUCCENTURIATE LOBE, esp when this lobe is noted to be some distance from the rest of the placenta. A succenturiate lobe is an accessory placental lobe. in this case, bulk of the placenta is implanted in one portion of the uterine wall, but a small lobe of the placenta is implanted in another location. the vessels that connect these two portions of the placenta are unrpotected and may cross over cervix nand present as a vasa previa, making them vulnerable to compression by the presenting fetal part or ttorn when membranes are ruptured.

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Question 31

sinusoidal pattern on a continuous fhr monitoring indicates fetal anemia. fetal anemia caused by rupture of fetal veessels upon rupture of membranes.

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Question 32

hemodynamic instability, significant vaginal bleeding, rigid abdomen, along with severe abdominal pain, most likely clinical diagnosis is placental abruption. normal labor does not cause significant blood loss with cervical change except in the instance of placenta previa.

initial elevated bp of 180/100 suggests preeclampsia or superimposed preeclampsia, which is known risk factor for placental abruption . vasa previa can lead to profuse vaginal bleeding if a patient ruptures her membranes and fetal vessels also rupture.

Answer 32

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