Bleeding Late in Pregnancy When the placenta misbehaves Grace Cavallaro MD, FACOG
Jan 03, 2016
Bleeding Late in Pregnancy
When the placenta misbehaves
Grace Cavallaro MD, FACOG
ObjectivesObjectives
• Identify major causes of vaginal bleeding second half of pregnancy
• Describe a systematic approach to identify the cause of bleeding
• Describe specific treatment options based on diagnosis
Causes of Late Pregnancy Bleeding
• Placenta Previa• Abruption• Ruptured Vasa Previa• Uterine Scar Disruption• Cervical Polyp• Bloody Show• Cervicitis• Vaginal Trauma• Cervical Cancer
LifeThreatening*
Placenta Previas
Placenta Previas
Prevalence of Placenta Previa
• Occurs in 1/200 pregnancies that reach 3rd trimester
• Low-lying placenta seen in 50% of ultrasound scans at 16-20 weeks– 90% will have normal implantation when scan
repeated @ >30 weeks– No proven benefit to routine screening
ultrasound for this diagnosis.
Risk factors for previa
• Previous Cesarean Sections• Previous Uterine Instrumentation• High Parity• Advancing Maternal Age
– Women over 40 have a RR of 9.0
• Smoking• Multiple Gestation
Morbidity with Placenta Previa
• Maternal Hemorrhage
• Operative Delivery Complications
• Transfusion
• Placenta accreta, increta or percreta
• Prematurity
Placenta Migration
• Migration means the dynamic relationship between the placenta and the internal os
• Trophotropism vs elongating lower uterine segment!
Previous C-sections and Previas
Number of Previous C-sections
Relative Risk for a Previa
1 4.5
2 7.4
3 6.5
4 or more 44.9
Anath ObGyn 1996
Patient History - Placenta Previa
• Painless Bleeding*– 2nd or 3rd trimester, or at term– Often following intercourse– May have preterm contractions*
• Sentinel Bleed– From large central previa– @ 26-28 weeks gestation
Physical Exam-Placenta Previa
• Vital Signs
• Assess Fundal Height
• Fetal Lie
• Estimated Fetal Weight (Leopold)
• Presence of fetal heart tones
• Gentle Speculum Exam
• No digital exam unless placental location known
Speculum exam revealing an anterior placenta previa
Laboratory - Placenta Previa
• Hematocrit or complete blood count
• Blood Type and Rh
• Coagulation tests
• (While waiting - serum clot tube taped to the wall)
Ultrasound - Placenta Previa
• Can confirm diagnosis
• Full bladder can create false appearance of anterior previa
• Presenting part may overshadow posterior previa
• Transvaginal scan can locate placental edge and internal os
The Placenta’s Ultrasound Appearance
Echodense placental tissue
Echolucent myometrialArea rich in blood supply
Vagina and Cervix meet at 90 degrees
Careful insertion of the vaginal probe midway into the vagina will image the LUS and the cervical os
Complete Previa - Ultrasound
c
c
Posterior Previa
Transvaginal ScanPosterior PlacentaPrevia
False Previa
Lower placental border
c
Full bladderNo Previa
False Previa - Overdistended Bladder
Bladder
c
Cervical canal
Placental Edge by U/S and Route of Delivery
• >2 cm os - placenta edge = safe for vaginal delivery
• <1cm os - placenta edge - Cesarean delivery
• 1-2 cm = may be able to deliver vaginal
– Dawson et al Jultrasound Medicine 1996
Ultrasound’s Role
• Previa = usually definitive except in very low lying posterior placentas in the obese patient
• Abruption - definitive diagnosis is not possible
• Transvaginal Scanning is safe in the bleeding patient
Clinical Signs and Clinical Signs and SymptomsSymptoms
• Painless Bleeding = Previa
• Painful Bleeding = Abruption
• Painless Fetal Bleeding = Vasa Previa
Initial managementInitial management
• 1) ABC’s1) ABC’s– Amount of bleeding noted is Amount of bleeding noted is
unreliableunreliable
• 2) Fetal Well Being2) Fetal Well Being• 3) No Vaginal Exams3) No Vaginal Exams
– Until you know where the Until you know where the placenta is!placenta is!
• 4) Ultrasound4) Ultrasound
Fetal/Neonatal Considerations
• Gestational Age of Fetus dictates local of care
• SGA/Prematurity are major problems
• Communication with consultants is key!
Cesarean Sections and Previas
• Pre-op Scan• Patients with Previas
undergoing C-Section– Bleed More– Require More Blood
Transfusion– Require More C-
Hysterectomies– Placenta accreta may
accompany 10%• Bladder invasion may be
associated with– DIC and massive hemorrhage
Treatment Placenta Previa
• With no active bleeding– Expectant management
– No intercourse, digital exam
– Rescan after 30 weeks
• With late pregnancy bleeding– Assess overall status, circulatory stability
– Full dose Rhogam if Rh -
– Consider maternal transfer if premature
– May need corticosteroids, tocolysis, amniocentesis
Expectant Management
• May discharge home if stable after 72 hours of inpatient observation.
• Reduces stay in hospital by average of 14 days.
• No increase in– Hemorrhage– Need for transfusion– Poor maternal or neonatal outcomes
Tocolytics in Placenta Previa
• Greatest morbidity and mortlity related to prematurity.
• Tocolytics can add an additional 11 days to pregnancy.– Allows for administration of corticosteroids– No increase in maternal or fetal complications– Increase birth weights average of 320 grams
Double Set-up Exam: digital exam in OR with ability to do immediate CD
• Appropriate only in marginal (anterior) previa with vertex presentation
• Palpation of placental edge and fetal head with set up for immediate surgery
• Cesarean delivery under regional anesthesia if– Complete previa– Fetal head not engaged– Non-Reassuring tracing – Brisk or Persistant bleeding– Mature fetus
Placental Abruption
• Premature separation of placenta from uterine wall– Partial or Complete
• “Marginal sinus separation” or “marginal sinus rupture”– Bleeding, but abnormal
implantation or abruption never established
Epidemiology of Abruption*
• Occurs in 1-2% of all pregnancies• Risk Factors
– Hypertensive diseases of pregnancy– Smoking or substance abuse*– Trauma*– Overdistension of the Uterus*– History of Previous Abruption*– Unexplained elevation of MSAFP– Placental insufficiency– Maternal Thrombophilia/Metabolic abnormalities
Abruptions and Trauma
• Can occur with blunt abdominal trauma and rapid deceleration without direct trauma
• Complications include prematurity, growth restriction and stillbirth
• Fetal evaluation after trauma– Increased use of FHR monitoring may decrease
mortality
Bleeding from Abruption
• Externalized hemorrhage
• Bloody amniotic fluid
• Retroplacental clot– 20% occult
– “uteroplacental apoplexy or Couvelaire uterus
• Look for consumptive coagulopathy
““Uteroplacental apoplexy or Couvelaire” uterusUteroplacental apoplexy or Couvelaire” uterus
Cigarette Smoking as Risk factor
• Nova Scotia Registry of 87, 184 pregnancies
• 33% smoked• 2.05 Relative Risk of Abruption• 1.75 Relative Risk of Previa• No dose effect noted
• Anath AmJ of Epidemiology 1996
Cocaine/Metamphetamine
• Associated with – chorionic villous
hemorrhage– Villous edema– Even in the absence of
clinical abruption placenta
Patient History: Abruption
• Pain = hallmark symptom*– Varies from mild cramping to severe pain
– Back Pain - think posterior abruption
• Bleeding– May not reflect amount of blood loss*
– Differentiate from exuberant bloody show
• Trauma• Other risk factors (e/g hypertension/drugs)• Membrane rupture
Physical Exam- Abruption
• Signs of circulatory instability– Mild tachycardia normal– Signs and symptoms of shock represent > 30%
blood loss
• Maternal abdomen– Fundal height– Leopold’s:estimated fetal weight, fetal lie– Location of tenderness– Tetanic contractions
Fetal/Uterine Monitor in an Abruption
Ultrasound Abruption
• Abruption is a clinical diagnosis!*
• Placental location and appearance– Retroplacental echolucency– Abnormal thickening of placenta– “Torn” edge of placenta
• Fetal lie
• Estimated fetal weight
Placental Abruption
Hemorrhage isoechoic with placenta Hematoma retroplacental
Abruption - Retroplacental Hematoma
Retro placental hematoma day1 7 days later
False Abruption? Contraction Mimicking Abruption
Contraction
No Contraction 30 minutes later
Placenta Lakes
Subchorionic Placental Lake
Doppler revealing flow through the lake
Laboratory-Abruption
• Complete blood count• Type and Rh• Coagulation tests + “Clot test”• Kleihauer-Betke test not
diagnostic, but useful to determine Rhogam dose
• Pre-eclampsia labs, if indicated• Consider urine drug screen
Sher’s Classification
Grade IMild, often retroplacental clot identified at delivery
Grade IITense, tender abdomen and live fetus
Grade III
-IIIA
-IIIB
With fetal demise
-without coagulopathy (2/3)
-with coagulopathy (1/3)
Treatment-Grade II Abruption
• Assess fetal and maternal stability
• Amniotomy
• IUPC to detect elevated uterine tone
• Expeditious operative or vaginal delivery
• Maintain urine output > 30 cc/hr and hemotocrit > 30%
• Prepare for neonatal resuscitation
Treatment - Grade III Abruption
• Assess mother for hemodynamic and coagulation status
• Vigorous replacement of fluid and blood products
• Vaginal delivery preferred, unless severe hemorrhage
Coagulopathy with Abruption
• Occurs in 1/3 of Grade III abruptions
• Usually not seen if live fetus
• Etiologies: consumption, DIC
• Administer platelets, FFP
• Give Factor VIII if severe
Epidemiology of Uterine Rupture*
• Occult dehiscence vs.. symptomatic rupture• .03%-.08% of all women• .03%-1.7% of all women with uterine scar• Previous cesarean incision most common
reason for scar disruption• Other causes: previous uterine curettage or
perforation, inappropriate oxytocin usage, trauma, drugs*
Risk Factors - Uterine Rupture*
• Previous Uterine Surgery*
• Congenital Uterine Anomalies
• Uterine Overdistension*
• Gestational Trophoblastic Disease
• Adenomyosis• Fetal Anomaly• Vigorous Uterine
Pressure• Difficult Placental
Removal• Placenta Increta or
Percreta (US/MRI)
During labor or delivery
Extension of Transverse
Scar
Midline Classical Rupture
CatastrophicRupture
Uterine Scar Disruption
Morbidity with Uterine Rupture
• Maternal– Hemorrhage with anemia– Bladder rupture– Hysterectomy– Maternal Death
• Fetal– Respiratory distress– Hypoxia– Acidemia– Neonatal death
Patient History -Uterine Rupture*
• Vaginal Bleeding• Pain• Cessation of contractions*• Absences FHR• Loss of Station• Palpable fetal parts through
maternal abdomen• Profound maternal tachycardia
and hypotension
Uterine Rupture• Sudden deterioration of FHR pattern is a
most frequent finding• Placenta may play a role in uterine rupture
• Transvaginal ultrasound to evaluate uterine wall• MRI to confirm possible placenta accreta
• Treatment• Asymptomatic scar disruption* - expectant
management• Symptomatic rupture - emergent cesarean
delivery
Vasa Previa
Bridging vessels
Vasa Previa
• Rarest cause of hemorrhage• Onset with membrane rupture• Blood Loss is fetal, with 56% mortality (3%)• Associated with placenta previa, velamentous
insertion of the cord, bilobed/succenturiate lobe, or IVF
• Antepartum diagnosis– Amnioscopy– Color doppler ultrasound– Palpate vessels during vaginal examination
Diagnostic Tests - Vasa Previa
• Apt test - based on colorimetric response of fetal hemoglobin
• Wright stain of vaginal blood - for nucleated RBCs
• Kleihauer-Betke test - 2 hour delay prohibits its use
Modified Apt Test
• Several cc’s of blood from vagina
• Mix with Tap water
• Centrifuge
• Mix supernatant with NaOH
• Read Color in Two minutes
• Fetal = pink
• Adult = brown
Management Vasa Previa
• Immediate Cesarean Delivery if fetal heart non-reassuring
• Administer normal saline 10-20 cc/kg bolus to newborn, if found to be in shock after delivery
Summary
• Late pregnancy bleeding may herald diagnoses with significant morbidity/mortality
• Determining diagnosis important as treatment dependent on cause
• Avoid vaginal exam when placental location not known!
Transvaginal Predictive Value
• TVS Overlap of 10 mm or more @ 15-20 weeks predictive 100% previa at term
– Lauria US ObGyn Nov 1996
• TVS Overlap of 15 mm @ 12-16 weeks predictive at birth 5.1 %
– Taipale ObGyn 1997
Risk factors for Abruptions
• Younger Women RR 1.4– Parity > 3 RR 10– May reflect effects of close pregnancy
spacing
• Previous Abruption RR 10• Chronic Hypertension• Preeclampsia RR 1.7• PROM RR 3.0