OBS - Obstetric Haemorrhage (inc APH & PPH)

Question 1

Antepartum Haemorrhage

Definition
Severity of Antepartum Haemorrhage
Differential Diagnoses

Answer 1

1. ) Definition - bleeding from the birth canal after the 24th week of pregnancy until the 2nd stage of labour
   - bleeding after birth is a postpartum haemorrhage
   - bleeding before 24wks is a miscarriage
2. ) Severity of Antepartum Haemorrhage
   - spotting: spots of blood noticed on underwear
   - minor: < 50ml blood loss, major: 50-1000ml loss
   - massive: >1000ml blood loss or signs of shock
3. ) Differential Diagnoses
   - placenta praevia including marginal placental bleed
   - placental abruption, vasa praevia, uterine rupture
   - lesions: ectropion (common), polyps, carcinoma
   - infections: candida, bacterial vaginosis, chlamydia

Question 2

Placenta Praevia

Definition
Risk Factors
Clinical Features

Answer 2

1. ) Definition - when the placenta is attached in the lower portion of the uterus (lower than the presenting part of the fetus) and is over the internal cervical os
   - low-lying placenta: is used when the placenta is within 20mm of the internal cervical os
2. ) Risk Factors
   - previous placenta praevia or C-sections
   - older maternal age, maternal smoking
   - structural uterine abnormalities e.g. fibroids
   - assisted reproduction e.g. IVF
3. ) Clinical Features - often asymptomatic
   - usually diagnosed in the 20-week anomaly USS
   - may present with painless vaginal bleeding (APH), usually occurring later in pregnancy (36+ weeks)
   - there may be malpresentation or failure of the fetal head to engage

Question 3

Management of Placenta Praevia

General Management
Delivery
Complications/Risks of Placenta Praevia

Answer 3

1. ) General Management
   - transvaginal USS: to determine placental position (repeat USS at 32 and 36 weeks if already known about)
   - DVE is contraindicated as it may provoke a severe haemorrhage
   - potential treatments for haemorrhage include:
   - blood transfusions, intrauterine balloon tamponade
   - uterine artery occlusion
   - emergency C-section or emergency hysterectomy
2. ) Delivery - early planned delivery
   - corticosteroids between weeks 34-36 (35+6) to mature fetal lungs due to risk of preterm delivery
   - early C-section is considered between 36-37wks to reduce the risk of spontaneous labour and bleeding
   - emergency C-section may be required with premature labour or antenatal bleeding
   - may need different incisions (e.g. vertical incision) depending on the position of the placenta and fetus
3. ) Complications/Risks of Placenta Praevia
   - ↑ morbidity and mortality for the mother and fetus
   - APH, maternal anaemia and transfusions
   - emergency C-section or hysterectomy
   - preterm birth, low birth weight, stillbirth

Question 4

Placental Abruption

Pathophysiology
Concealed Abruption
Risk Factors
Clinical Features

Answer 4

1. ) Pathophysiology - premature separation of part (or all) of the placenta from the uterine wall due to rupture of maternal vessels within the endometrial basal layer
   - blood accumulates and splits the placenta from the basal layer, the detached portion of the placenta is unable to function, leading to rapid fetal compromise
   - site of attachment can bleed extensively after the placenta separates which may cause significant APH
2. ) Concealed Abruption
   - cervical os remains closed so bleeding remains w/in the uterine cavity so can be severely underestimated
   - the bleeding typically forms a clot retroplacentally
   - can be severe enough to cause systemic shock
   - normal abruption is known as ‘revealed’ abruption
3. ) Risk Factors - ABRUPTION
   - Abruption previously, Blood Pressure (high BP)
   - Ruptured membranes, Uterine injury (abdo trauma)
   - Polyhydramnios, Twins (or multiple gestation)
   - Infection in the uterus (especially chorioamnionitis)
   - Older age (>35), Narcotic use (smoking, cocaine, amphetamine use)
   - others: abnormal lie, growth restriction, multigravida, bleeding in T1, underlying thrombophilia
4. ) Clinical Features - clinical diagnosis
   - painful vaginal bleeding (can be concealed)
   - sudden onset severe and continuous abdominal pain, if in labour, can have pain in between contraction
   - characteristic ‘woody’ abdomen on palpation is suggestive of a large haemorrhage, tense, firm uterus
   - haemodynamic shock: hypotension and tachycardia
   - fetal distress: abnormalities on the CTG

Question 5

Management of Placental Abruption

Investigations
General Management
Delivery

Answer 5

1. ) Investigations
   - FBC, clotting, crossmatch/G+S
   - U+Es and LFT: to exclude hypertensive disorders inc pre-eclampsia and HELLP syndrome
   - Kleihauer test: to determine dose of anti-D required
   - USS: used to exclude placenta praevia, may see retroplacental haematoma but this is not reliable
   - CTG (if >26wks) to assess fetal wellbeing
2. ) General Management - obstetric emergency
   - any significant APH requires resuscitation (using A-E), do not delay resus to determine fetal viability
   - escalate to senior O+G, midwife, or anaesthetist
   - if the fetus is alive, <36wks, and there’s no fetal distress, give steroids, anti-D (w/in 72hrs if Rh-ve) and observe closely (do not administer tocolysis)
3. ) Delivery
   - fetal distress at any time: CAT1-section (unless spontaneous delivery is imminent)
   - fetus is >36 weeks (dead or alive): vaginal IOL

Question 6

Vasa Praevia

Pathophysiology
Types of Vasa Praevia
Clinical Features
Management

Answer 6

1. ) Pathophysiology - fetal vessels travel across the internal cervical os so are in between the fetus
   - due to fetal vessels becoming exposed outside the protection of the umbilical cord or placenta
   - exposed vessels are prone to bleeding, esp when the membranes are ruptured during labour and at birth
   - this can lead to dramatic fetal blood loss and death
   - RFs: low lying placenta, IVF, multiple pregnancy
2. ) Types of Vasa Praevia
   - Type I: fetal vessels are exposed as a velamentous umbilical cord (inserts into chorioamniotic membranes, causing the fetal vessels to travel unprotected through the membranes before joining the placenta)
   - Type II: fetal vessels are exposed in fetal membranes as they travel to an accessory placental lobe
3. ) Clinical Features
   - can be diagnosed via USS, however, it is often not possible to diagnose antenatally so this is not reliable
   - may present with APH during T2 or T3 of pregnancy
   - may be detected during labour via:
   - DVE: pulsating vessels seen in the membranes
   - fetal distress and dark-red bleeding occur following rupture of the membranes (very high fetal mortality)
4. ) Management
   - asymptomatic women (seen in USS): corticosteroids from 32wks and elective C-section for 34-36 weeks
   - APH: emergency C-section to prevent stillbirth
   - after stillbirth or unexplained fetal compromise during delivery, the placenta is examined for evidence of vasa praevia as a possible cause