Vaginal Bleeding in Late Pregnancy

Objectives Identify major causes of vaginal bleeding in the second half of pregnancy Describe a systematic approach to identifying the cause of bleeding Describe specific treatment options based on diagnosis

Causes of Late Pregnancy Bleeding Placenta Praevia Abruption Ruptured vasa praevia Uterine scar disruption Cervical polyp Bloody show Cervicitis or cervical ectropion Vaginal trauma Cervical cancer Life-threatening

Prevalence of Placenta Praevia 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 at > 30 weeks No proven benefit to routine screening ultrasound for this diagnosis

Risk Factors for Placenta Praevia Previous caesarean delivery Previous uterine instrumentation High parity Advance maternal age Smoking Multiple gestation

Morbidity and Placenta Praevia Maternal haemorrhage Operative delivery complications Transfusion Placenta accreta, increta or percreta Prematurity

Patient History – Placenta Praevia Painless bleeding 2nd or 3rd trimester, or at term Often following intercourse May have preterm contractions “Sentinel bleed”

Physical Exam – Placenta Praevia Vital signs Assess fundal height Fetal lie Estimated fetal weight (Leopold) Presence of fetal heart tones Gentle speculum exam No digital vaginal exam unless placental location known

Laboratory – Placenta Praevia Haematocrit or complete blood count Blood type and Rh Coagulation tests

Ultrasound – Placenta Praevia Can confirm diagnosis Full bladder can create false appearance of anterior praevia Presenting part may overshadow posterior praevia Transvaginal scan can locate placental edge and internal os

Treatment – Placenta Praevia With no active bleeding Expectant management No intercourse, digital exams With late pregnancy bleeding Assess overall status, circulatory stability Full dose Rhogam if Rh- Consider maternal transfer if premature May need corticosteroids, tocolysis, amniocentesis

Double Set-Up Exam Appropriate only in marginal praevia with vertex presentation Palpation of placental edge and fetal head with set up for immediate surgery Caesarean delivery under regional anaesthesia if: complete praevia fetal head no engaged non-reassuring tracing brisk or persistent bleeding mature foetus

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 pregnancies Risk factors hypertensive diseases of pregnancy smoking or substance abuse (e.g. cocaine) trauma overdistension of the uterus history of previous abruption unexplained elevation of MSAFP placental insufficiency maternal thrombophilia/metabolic abnormalities

Abruption and Trauma Can occur with blunt abdominal trauma and rapid deceleration without direct trauma Complications inculde prematurity, growth restriction, 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 “Couverlaire” uterus Look for consumptive coagulopathy

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 blood show Trauma Other risk factors (e.g. hypertension) Membrane rupture

Physical Exam - Abruption Signs of circulatory instability Mild tachycardia normal Signs and symptoms of shock represent > 30% blood test Maternal abdomen Fundal height Leopold’s estimated fetal weight, fetal lie Location of tenderness Tetanic contractions

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

Laboratory - Abruption Complete blood count Type and Rh Coagulation tests Kleihauer-Betke not diagnostic, but useful to determine Rhogam dose Preeclampsia labs, if indicated Consider using drug screen

Sher’s Classification - Abruption Grade I mild, often retroplacental clot identified at delivery Grade II tense, tender abdomen and live fetus Grade III III A III B 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 > 30cc/hr and haematocrit > 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 haemorrhage

Coagulopathy with Abruption Occurs in 1/3 of Grade III abruption 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 0.03-0.08% of all women 0.3-1.7% of women with uterine scar Previous caesarean incision most common reason for scar disruption Other causes: previous uterine curettage or perforation, inappropriate oxytocin usage, trauma

Risk Factors – Uterine Rupture adenomyosis fetal anomaly vigorous uterine pressure difficult placental removal placenta increta or percreta pervious uterine surgery congenital uterine anomaly uterine overdistension gestational trophoblastic neoplasia

Morbidity with Uterine Rupture Maternal haemorrhage with anaemia bladder rupture hysterectomy maternal death Fetal respiratory distress hypoxia acidaemia neonatal death

Patient History – Uterine Rupture Vaginal bleeding Pain Cessation of contractions Absence of FHR Loss of station Palpable fetal parts through maternal abdomen Profound maternal tachycardia and hypotension

Uterine Rupture Sudden deterioration of FHR pattern is most frequent finding Placenta may play a role in uterine rupture Transvaginal ultrasound to elevate uterine wall MRI to confirm possible placenta accreta Treatment Asymptomatic scar disruption – expectant management Symptomatic rupture – emergent caesarean delivery

Vasa Praevia Rarest cause of haemorrhage Onset with membrane rupture Blood loss is fetal, with 50% mortality Seen with low lying placenta, velamentous insertion of the cord or succenturiate lobe Antepartum diagnosis amnioscopy colour doppler ultrasound palpate vessels during vaginal examination

Diagnostic Tests – Vasa Praevia Apt test – based on colorimetric response of fetal haemoglobin Wright stain of vaginal bleed – for nucleated RBCs Kleihauer-Betke test – 2 hour delay prohibits its use

Management – Vasa Praevia Immediate caesarean delivery if fetal hear rate non-assuring 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