Lucan · Conditions

Postpartum haemorrhage

Australian guidance: RANZCOG C-Obs 43 PPH Management (2021)

1. Definition and epidemiology

Postpartum haemorrhage (PPH) is defined as blood loss of 500 mL or more during the puerperium, with severe PPH defined as blood loss of 1000 mL or more; more recently, PPH is considered severe when there are signs of haemodynamic compromise regardless of estimated volume. In Australia, the incidence is between five and fifteen percent of all births, making PPH one of the most common obstetric complications. Despite the majority of cases being minor, PPH remains a leading cause of maternal death in Australia and New Zealand, underscoring the need for rapid, systematic management at all birthing facilities.

PPH is classified as primary (occurring within 24 hours of delivery) or secondary (occurring between 24 hours and six weeks postpartum).

2. Pathophysiology

Normal haemostasis at the placental bed depends on two coordinated mechanisms. First, uterine smooth muscle contraction physically compresses the spiral arteries supplying the placental bed, reducing blood flow from approximately 750 mL per minute at term to near zero. Second, conventional coagulation cascades involving vasoconstriction, platelet aggregation and fibrin clot formation seal the denuded decidual vessels. Failure of either limb produces PPH. The four aetiological categories are summarised by the mnemonic "four Ts": Tone (uterine atony, the most common cause), Trauma (lacerations, uterine rupture, broad ligament haematoma), Tissue (retained placenta, cotyledon, or membranes that prevent sustained uterine contraction), and Thrombin (coagulopathies including disseminated intravascular coagulation, thrombocytopenia, von Willebrand disease, and anticoagulant medications). A fifth "T" for Theatre has been added to highlight the role of operative intervention in managing all causes. Uterine overdistension from multiple pregnancy, polyhydramnios or macrosomia, prolonged second stage of labour, high parity, and placenta accreta spectrum each independently impair the uterine contraction response and predispose to atony.

3. Clinical presentation and diagnostic criteria

Most cases of PPH occur without warning in women with no identifiable antepartum risk factors, so a high index of suspicion must be maintained for all postpartum women. Primary PPH presents with visible heavy vaginal bleeding within the first 24 hours after delivery. However, bleeding may be partly concealed within the uterine cavity or retroperitoneally, so clinical signs of haemodynamic compromise (tachycardia, hypotension, pallor, reduced consciousness) may precede obvious external haemorrhage. Uterine palpation reveals a soft, poorly contracted fundus in atony; a well-contracted uterus with ongoing bleeding redirects assessment to trauma or coagulopathy. Secondary PPH presents with uterine bleeding beyond 24 hours and is most commonly associated with endometritis and retained products of conception. Formal diagnostic criteria require blood loss at or above 500 mL for primary PPH or signs of haemodynamic instability at any volume.

4. Investigations and AU-specific cutoffs

Initial investigations should be obtained simultaneously with resuscitation and must not delay treatment. Draw blood for full blood count (FBC), coagulation screen (PT, INR, APTT, fibrinogen), biochemistry, and arterial blood gases; send a group-and-hold sample and activate cross-match early. Point-of-care testing such as ROTEM has an increasing role in guiding coagulation product replacement. AU-specific targets from the RANZCOG Massive Transfusion Protocol (MTP) template include: platelets above 50 x 10^9/L, PT and APTT less than 1.5 times normal, INR at or below 1.5, fibrinogen above 1.0 g/L, ionised calcium above 1.1 mmol/L, temperature above 35 degrees Celsius, pH above 7.2, lactate below 4 mmol/L, and base excess above negative six. Replace cryoprecipitate or fibrinogen concentrate when fibrinogen falls below 1.5 to 2 g/L. Invasive monitoring of arterial blood pressure or central venous pressure is indicated for significant PPH over 1000 mL or where haemodynamic instability persists. Ultrasound assists in identifying retained products or broad ligament haematoma in secondary or unexplained PPH.

5. Management

Management follows the RANZCOG five-component framework of recognition, communication, resuscitation, monitoring, and directed treatment, all initiated simultaneously.

Call for help immediately and assemble a multidisciplinary team including senior obstetrics, midwifery, anaesthesia, and haematology staff. Resuscitation uses an ABC approach: establish two large-bore intravenous cannulae, administer high-flow oxygen, and infuse warmed intravenous fluids rapidly. Group O Rh(D)-negative blood should be considered early to restore oxygen-carrying capacity when cross-matched blood is not yet available. Activate the institutional massive transfusion protocol for estimated blood loss over 1000 mL or ongoing haemodynamic instability.

Directed treatment addresses the causative "T" in a stepwise fashion. For atony, begin with uterine massage and bimanual uterine compression, progressing to uterotonics (see Section 6), and then to surgical intervention if pharmacological measures fail. For trauma, inspect the entire genital tract visually and repair under adequate anaesthesia. For retained tissue, attempt controlled cord traction; if unsuccessful, transfer to theatre for manual removal of the placenta. For coagulopathy, replace clotting factors as guided by laboratory values and ROTEM, prioritising early fibrinogen replacement.

Tranexamic acid 1 g intravenously should be given as soon as PPH is recognised and repeated at 30 minutes if bleeding persists, as demonstrated by the WOMAN trial to reduce mortality without adverse effects.

Surgical options when medical management fails include balloon tamponade (Bakri or Foley catheter), haemostatic brace suturing (B-Lynch suture), bilateral uterine artery ligation, bilateral internal iliac artery ligation, selective arterial embolisation (where interventional radiology is available without critical time delay), and ultimately peripartum hysterectomy. Hysterectomy should not be delayed in uterine rupture, placenta accreta spectrum, or uncontrolled massive haemorrhage.

Secondary PPH is managed with broad-spectrum antibiotics for presumed endometritis. Surgical evacuation of retained products should be considered for persistent or heavy secondary bleeding regardless of ultrasound findings.

Active management of the third stage of labour, comprising prophylactic oxytocics and controlled cord traction, reduces the risk of PPH by approximately 50% and should be offered to all women.

6. Pharmacology and AU PBS notes

Uterotonics are the pharmacological mainstay of both prevention and treatment of PPH and are commonly combined in severe cases.

Oxytocin (Syntocinon, PBS listed) is the first-line agent. For third-stage prophylaxis, give 5 to 10 units intramuscularly or slow intravenous injection. For treatment, administer 5 units by slow intravenous injection followed by an intravenous infusion of 40 units in 500 mL normal saline over four hours per local protocol. A repeat dose may be given if already used for third-stage management.

Ergometrine 0.25 mg by slow intravenous or intramuscular injection, repeated every five minutes to a maximum of 1.0 mg, is second-line. The fixed-dose combination Syntometrine (oxytocin 5 units plus ergometrine 0.5 mg) reduces the need for additional uterotonics but carries a higher side-effect burden including vomiting and hypertension; it is contraindicated in hypertension.

Misoprostol (prostaglandin E1 analogue) up to 1000 micrograms rectally may be used when oxytocin is unavailable or when response is inadequate. It is less effective than oxytocin in hospital settings but useful in low-resource contexts.

Carbetocin (long-acting oxytocin receptor agonist) is at least equivalent to oxytocin bolus plus infusion for caesarean birth and does not require refrigeration, making it suitable for resource-limited settings.

Prostaglandin F2-alpha analogues are the most potent uterotonics but carry the most serious adverse effects, including severe hypertension and bronchospasm; they are contraindicated in asthma. Following discontinuation of dinoprost trometamol in Australia, 15-methyl-PGF2-alpha (carboprost; Prostinfenem) is accessed via the TGA Special Access Scheme (SAS). Dosing is 0.25 mg intramuscularly every 15 minutes to a maximum cumulative dose of 2.0 mg (up to eight doses). Off-label intramyometrial use at 0.5 mg is practised but is not a manufacturer-approved route.

Tranexamic acid (antifibrinolytic) 1 g intravenously is given at PPH diagnosis and repeated at 30 minutes if bleeding persists; it is not a PBS-listed first-line uterotonic but is recommended by RANZCOG as part of overall PPH management.

7. Complications and monitoring

Immediate life-threatening complications include haemorrhagic shock, disseminated intravascular coagulation, acute renal failure from hypoperfusion, acute respiratory distress syndrome (especially with amniotic fluid embolism), and cardiac arrest. Peripartum hysterectomy, while lifesaving, results in permanent loss of fertility.

Clinical observations (pulse rate, blood pressure, oxygen saturation, urine output) must be recorded at frequent intervals throughout the acute event. In significant PPH over 1000 mL, monitoring should escalate to high dependency or intensive care unit level with invasive arterial and central venous pressure monitoring as clinically indicated. Repeat FBC, coagulation screen, ionised calcium, and arterial blood gases every 30 to 60 minutes during active haemorrhage, guided by the MTP monitoring protocol.

Longer-term sequelae to monitor include Sheehan syndrome (pituitary necrosis from prolonged hypoperfusion, presenting with failure to lactate and secondary amenorrhoea), iron-deficiency anaemia requiring oral or intravenous iron supplementation, post-traumatic psychological morbidity, and venous thromboembolism risk, for which pharmacological prophylaxis should be reinstated once haemostasis is secured.

Antenatal correction of anaemia in women at elevated risk of PPH is an important preventive measure, and all women should birth in a facility with rapid access to blood products and a clearly defined massive transfusion protocol.

Written for Australian practice and grounded in the guidance named above. Study material only — not medical advice. Always check against current guidelines.