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90 Cards in this Set
- Front
- Back
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What are the four conditions that account for most cases of serious or life-threatening hemorrhage in late pregnancy? |
- Placenta previa - Placental abruption - Uterine scar disruption - Vasa previa |
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What are the non-emergent causes of bleeding in late pregnancy? |
- Cervical dilatation during normal labor which is often accompanied by a small amount of blood or blood-tinged mucus (bloody show) - Many women experience spotting or minor bleeding after sexual intercourse or digital vaginal exam - Cervicitis, cervical ectropion, cervical polyps, and cervical cancer are other possible causes of minor bleeding |
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What are the steps for differentiating the minor from serious causes of vaginal bleeding? |
- History - Physical exam - sterile speculum exam may be performed prior to U/S, but digital exam should not be performed until U/S rules out placenta previa - U/S for placental location - Brief period of observation |
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Risk factors for placenta previa? |
- Chronic HTN
- Multiparity - Multiple gestations - Older age - Previous C/S (2.3% in woman having their 3rd C/S) - Tobacco use - Uterine curettage - Male fetal gender |
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Risk factors for placental abruption? |
- Chronic HTN - Multiparity - Pre-eclampsia - Previous abruption - Short umbilical cord - Sudden decompression of an over distended uterus - Thrombophilias - Tobacco, cocaine, or methamphetamine use - Trauma - blunt abdominal or sudden deceleration - Unexplained elevated maternal alpha fetoprotein level - Uterine fibroids |
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Risk factors for uterine rupture? |
- Abnormal placentation - History of uterine surgery - Maternal connective tissue disease - Uterine anomalies - Trauma - Trial of labor after cesarean section (TOLAC) |
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Risk factors for vasa previa? |
- Fetal anomalies - In vitro fertilization - Low-lying and second trimester placental previa - Marginal cord insertion - Multiple gestation - Succenturiate-lobed and bilobed placentas |
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What is the initial management for significant bleeding in late pregnancy? |
- Vital signs - assessment for circulatory instability - Establish IV access - Prompt fluid resuscitation |
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What does tachycardia signify with vaginal bleeding in late pregnancy? |
- Mild tachycardia is normal in pregnancy - Orthostatic changes in BP or HR may be significant - More severe tachycardia indicating hemodynamic instability is an ominous indicator with hypotension |
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Signs and symptoms of shock are late findings in pregnant women and represent what percent of blood volume loss? |
30% |
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What should you assess on physical exam of a woman with vaginal bleeding in late pregnancy? |
- Fundal height - Estimated fetal weight - Fetal presentation - Location of tenderness - Assess for contraction |
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What baseline labs should be gotten for a woman with vaginal bleeding in late pregnancy? |
- Hematocrit - Platelet count - Fibrinogen level - Coagulation studies - Blood type - Antibody screen - Consider pre-eclampsia labs or a urine drug screen |
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What does a fibrinogen level tell you? |
<250 is abnormal <150 is diagnostic of coagulopathy |
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Which women presenting with vaginal bleeding in late pregnancy should receive Rho(D) immune globulin (Rhogam)? |
All women who are Rh negative |
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How do you determine the dose of Rhogam for Rh negative women presenting with vaginal bleeding in late pregnancy?
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Kleihauer-Betke test |
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How do you determine whether a woman with vaginal bleeding in late pregnancy should get an urgent operative delivery? |
Continuous fetal monitoring - Fetal heart rate decelerations, tachycardia, or loss of variability may resolve with adequate maternal resuscitation, however if they persist, may require delivery before etiology of bleeding is determined |
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What is placenta previa? |
When the placenta implants overlying or in close proximity to the internal cervical os |
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Where does the placenta normally implant? |
Near the fundus (during pregnancy, the placenta may appear to migrate towards the fundus due to the richer blood supply and also due to elongation of the lower uterine segment) |
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What may cause abnormal implantation of the placenta? |
Disruption or scarring of the uterine cavity |
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How do you diagnose placenta previa? |
Transvaginal U/S - precise assessment of distance between internal os and placental edge |
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What is a complete placental previa? |
Placenta covers the internal os |
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What is a marginal placental previa? |
Placental edge lies within 2 cm of the os |
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What is a low-lying placental previa? |
Placental edge within 2 - 3.5 cm of the os |
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How common is a placenta previa during the second trimester (~20-25 weeks)? |
4% |
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How common is a placenta previa at term? |
0.4% |
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What can lead to maternal morbidity with placenta previa? |
- Maternal hemorrhage (exsanguination rarely occurs unless instrumentation or digital exam is performed) - C-section - Abnormal placental attachment (placenta accreta, increta, or percreta) |
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Risk factors for abnormal placental attachment? |
Women who have had a prior C/S and have a placenta previa or low anterior placenta in subsequent pregnancies (risk ~10%)
Risk also increases with number of previous C/S |
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How can you evaluate for placenta accreta? |
Color-flow Doppler MRI |
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How should you prepare for delivery for a woman with a suspected placenta accreta? |
Prepare for possible cesarean hysterectomy and have adequate blood available |
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Typical clinical presentation of placenta previa? |
- Vaginal bleeding in late 2nd or 3rd trimester, often after sexual intercourse - Bleeding is painless unless labor or placental abruption occur - Large central previa will typically present with bleeding at 26-28 weeks ("sentinel bleed") - usually not significant enough to cause hemodynamic instability or to threaten fetal life in absence of cervical instrumentation or digital exam |
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What should you suspect in a patient who has a persistent malpresentation? Why? |
Placenta previa - due to presence of a large placenta filling the pelvis |
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How do you diagnose placenta previa? |
U/S - transvaginal |
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How should placenta previa be managed? |
- Outpatient management after initial inpatient observation is appropriate if no active bleeding and have rapid access to hospital with operative L&D services - Asymptomatic previa in 2nd trimester canc continue normal activities until follow-up US at 28 weeks - If persistent previa in 3rd trimester, instruct to report any bleeding and abstain from intercourse and use of tampons - When bleeding occurs, admit to hospital |
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How should neonatal morbidity and mortality from placenta previa be addressed? |
Usually due to complications of prematurity, so goal is to prolong pregnancy until fetal lung maturity is achieved Tocolytic agents can be used if vaginal bleeding occurs with preterm contractions Corticosteroids should be given between 24-34 weeks if they have bleeding |
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What is the evidence for cervical cerclage for management of placenta previa? |
- In Cochrane review, cerclage decreased risk of premature birth before 34 weeks - Recommended there be additional studies of cerclage before this clinical practice is introduced |
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What factor can predict the need for emergency C/S in patients with placenta previa? |
Cervical length <31 mm on transvaginal U/S (need for C/S is 2/2 massive hemorrhage before 34 weeks) |
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What factor determines the need for C/S vs vaginal delivery for women with a marginal previa? |
No decision should be made until U/S at 36 weeks |
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For women with placenta >2 cm from internal cervical os, what type of delivery is likely? |
Expect vaginal delivery unless heavy bleeding ensues |
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For women with placenta 1-2 cm from internal cervical os, what type of delivery is likely? |
May attempt vaginal delivery in a facility capable of moving rapidly to C/S if necessary (~70% can achieve vaginal delivery without increased hemorrhage) |
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What are the indications for an operative delivery with placenta previa? |
- Persistent, brisk vaginal bleeding which poses a threat to stability of maternal-fetal dyad - Vaginal bleeding in pregnancy where fetus is sufficiently mature to be delivered safely |
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What is placental abruption? |
Separation of placenta from uterine wall before delivery |
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What is the most common cause of serious vaginal bleeding? |
Placental abruption (1% of pregnancies) |
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Why is the rate of placental abruption increasing? |
Rising rates of HTN and stimulant abuse and increased diagnosis by U/S |
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Pathophysiology / causes of placental abruption? |
- Abnormalities in placental development and implantation that start in 1st trimester - Blunt trauma - Vasoconstriction associated with cocaine use - Sudden uterine decompression after rupture of membranes or delivery of a first twin |
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How can the risk for placental abruption be decreased?
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- Cessation of tobacco, cocaine, or amphetamine use - Appropriate care of HTN disorders of pregnancy |
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Clinical presentation for placental abruption? |
- Vaginal bleeding with abdominal pain (from mild cramping to severe pain) - Back pain (if posterior placental abruption) vs abdominal pain (anterior placental abruption) - If caused by trauma, may have pain without bleeding (concealed hemorrhage) |
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What percentage of placental abruptions may be "concealed hemorrhages"? |
20-63%
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What history should be gathered from a woman with painful vaginal bleeding? |
- Trauma (including domestic violence) - Presence of pain and contractions - Rupture of membranes - Assessment of risk factors - Hx of HTN (or s/s of pre-eclampsia) - Hx of stimulant use (cocaine, amphetamine) |
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What is the typical appearance of blood from concealed hemorrhage? |
Dark, having been sequestered behind membranes |
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Does the quantity of vaginal bleeding correlate with severity of abruption? |
No |
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If bleeding is noted at the time of rupture of membranes, what diagnosis should be considered? |
- Placental abruption
- Vasa previa |
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Physical examination / diagnostic testing in woman suspected of having placental abruption? |
- Fetal heart tones - Uterine activity - U/S |
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What do you look for on U/S when suspecting placental abruption?
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- Retroplacental clot or hemorrhage - Acute blood clots and placenta are both hyper echoic and can be difficult to distinguish - If mother and fetus are stable, also evaluate placental location, appearance, fetal lie, and fetal weight estimation - Possible signs of abruption: retroplacental echo lucency, abnormal thickening of placenta, or abnormally round "torn up" edge of placenta |
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What other imaging modality can be used to diagnose placental abruption? |
CT |
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How should a mild placental abruption be managed? |
Conservative manner can be used if small partial abruption and a preterm fetus Tocolysis is usually contraindicated except in mild abruption before 34 weeks to allow administration of corticosteroids |
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In a woman with a mild placental abruption that is managed conservatively, how should you interpret recurrent bleeding? |
Sign of chronic abruption
- Serial U/S for fetal growth - Antepartum surveillance due to potential for uteroplacental insufficency |
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How should a severe placental abruption be managed? |
- Maternal stabilization: monitor VS, UOP - Serial evaluation of hematocrit and coagulation studies - Neonatal resuscitation personnel should be present for delivery - Rh immunoglobulin in Rh negative patients (dose determined by Kleihauer-Betke test) |
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What is the goal UOP in severe placental abruption?
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>30 cc/hr |
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What is the goal hematocrit in severe placental abruption? |
>30% |
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Why should you monitor serial coagulation studies in severe placental abruption? |
To monitor for DIC |
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What factor necessitates rapid C/S for women with severe placental abruption? |
Non-reassuring fetal heart tracing - goal decision to delivery time <20 minutes
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What should be done when fetal death occurs secondary to placental abruption? |
Vaginal delivery should be the goal unless there are maternal indications for C/S (failure of labor progression, brisk hemorrhage that cannot be compensated for by transfusion) |
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How common is coagulopathy in placental abruption? |
1/3 of patients with fetal demise will develop coagulopathy (2/3 of patients will not develop coagulopathy) Coagulopathy is rare in patients with a live fetus |
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What is coagulopathy in placental abruption usually related to? |
- Consumptive coagulopathy - DIC |
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How should you manage coagulopathy in placental abruption? |
Replacement of platelets and FFP just prior to operative delivery to provide maximum efficacy Cryoprecipitate and Factor VIII may be of specific benefit in severe coagulopathy |
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Can you transfer a mother with severe placental abruption? |
Usually a live fetus is not stable for transfer since operative delivery may be needed on an immediate basis at any time during labor Neonatal transfer may be necessary for premature or sick newborn If fetal demise occurs, a patient who does not have coagulopathy and is hemodynamically stable may be cared for with appropriate resources; blood bank supply may determine whether they need transfer |
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What is the spectrum of pathology of uterine rupture? |
- Occult dehiscence that is not discovered until repeat C/S - Complete uterine rupture requiring emergency laparotomy (fetus or placenta may be partially or completely extruded from uterus) |
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How common is uterine rupture? |
0.03-0.08% 0.8% of women with a uterine scar |
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Most common etiology of uterine rupture? |
Previous C/S incision |
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Other causes of uterine rupture besides prior C/S? |
- Previous uterine curettage - Previous uterine perforation - Previous uterine surgery (eg, myomectomy involving full thickness of myometrium) - Inappropriate oxytocin usage - Trauma - Congenital uterine anomaly - Uterine overdistension - Intra-amniotic installation - Gestational trophopblastic neoplasia - Maternal obesity - Adenomyosis |
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What conditions during delivery can predispose to uterine rupture? |
- Fetal anomaly - Vigorous uterine pressure - Difficult manual removal of placenta - Abnormalities of placental implantation |
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What is the most common maternal morbidity associated with uterine rupture? |
Hemorrhage, subsequent anemia requiring blood transfusion |
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Besides hemorrhage / anemia, what other maternal morbidities are associated with uterine rupture?
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- Bladder injury - Hysterectomy (14-33% of uterine ruptures) |
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Clinical presentation of uterine rupture? |
- Vaginal bleeding, pain, cessation of contractions, absence of fetal heart tones, loss of station, easily palpable fetal parts through maternal abdomen, profound maternal tachycardia and hypotension - Most cases present initially with abnormal fetal monitoring (~70% of cases) / sudden deterioration of FHR pattern --> on exam, find recession of fetal head or suprapubic bulging |
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How should you instruct patients with a history of uterine scar differently from other patients? |
These patients should be advised to come to the hospital for evaluation of new onset contractions, abdominal pain, or vaginal bleeding as soon as possible |
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How should uterine rupture be managed? |
- Intrauterine resuscitation: maternal position change, IV fluids, discontinue oxytocin, O2 administration, consideration of subcutaneous terbutaline - If not effective, then emergent C/S or operative vaginal delivery |
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What is the only cause of major obstetric hemorrhage in which blood loss is primarily fetal? |
Vasa Previa |
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What is vasa previa? |
Insertion of umbilical cord into membranes in lower uterine segment, resulting in presence of fetal vessels between cervix and presenting part |
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What is the perinatal mortality in vasa previa? |
33-100% (this rate can be decreased with antenatal diagnosis) |
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Risk factors for vasa previa? |
- IVF - Placenta Previa - Bilobed and Succenturiate-lobed placentas |
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How do you diagnose vasa previa? |
Vaginal U/S w/ color flow doppler |
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How does vasa previa clinically present? |
- Onset of hemorrhage at time of amniotomy or spontaneous rupture of membranes - May be diagnosed by MRI, amnioscopy, intrapartum identification of fetal blood intermix diwth vaginal blood |
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How much blood volume is in the average term fetus? |
250cc |
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How should you manage suspected vasa previa if fetal heart rates are reassuring? |
Analyze blood sample from vaginal vault to check for fetal RBCs or fetal hemoglobin - Apt test - Wright stain - Kleihauer-Betke test and hemoglobin electrophoresis are too slow to use clinically |
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What are the results of the Apt test that distinguish fetal from adult blood? |
- If supernatant is pink it indicates fetal Hgb - If supernatant is brown it indicates adult Hgb |
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How does the Wright stain distinguish between fetal and adult blood? |
Look for nucleated RBCs, if present it is fetal blood (nucleated RBCs are uncommon in adult blood) |
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How should vasa previa be managed? |
Delivery should not be deferred for confirmation of fetal blood in women with severe hemorrhage or when fetal heart tones are non-reassuring If onset of vaginal bleeding occurred with rupture of membranes and fetal heart rate is not reassuring --> IMMEDIATE C/S Prepare for neonatal shock by having NS bolus available at 10-20cc/kg |
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What is the neonatal survival rate with vasa previa? |
- 97% if antenatal diagnosis - 44% without antenatal diagnosis |
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When there is antenatal diagnosis of vasa previa, how should the pregnancy be managed? |
- Serial U/S recommended to evaluate for regression of vessels (15% of women) - If persists, hospitalization at 30-32 weeks should be considered to allow for administration of corticosteroids and for proximity to operative delivery should membranes rupture - Out-pt management can be considered for asymptomatic women with long, closed cervix on U/S - Optimal gestations age is not determined, but C/S at 35-36 weeks is recommended to balance risk of respiratory distress syndrome with risk of membrane rupture and fetal exsanguination |
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How can vasa previa be prevented? |
No way to prevent vasa previa, but can theoretically prevent hemorrhage with antenatal screening and C/S at 35-36 weeks when vasa previa is present Screening is with transvaginal color-flow Doppler; not recommended in general population but is recommended for those at increased risk (eg, low lying bilobed or succenturiate lobed placenta or in women pregnant by IVF) |
