Postpartum Haemorrhage

Postpartum haemorrhage is excessive bleeding after childbirth. It is conventionally defined as blood loss exceeding 500 mL after vaginal delivery or 1000 mL after caesarean delivery.

It is a leading cause of maternal mortality worldwide and a significant cause of severe maternal morbidity even in well-resourced healthcare settings.

It is classified as primary or secondary. Primary haemorrhage occurs within the first twenty-four hours after delivery and accounts for the substantial majority of cases. Secondary haemorrhage occurs from twenty-four hours up to six weeks postpartum.

The causes are conventionally organised by the "four Ts" framework (tone, trauma, tissue, and thrombin). It gives a structured, systematic approach to diagnosis and management of this time-critical obstetric emergency.

Classification and pathophysiology

• Uterine atony (failure of adequate uterine contraction after delivery, "tone") is by a substantial margin the commonest cause of primary postpartum haemorrhage.
• Coordinated, sustained uterine contraction compresses the spiral arteries at the placental implantation site and achieves haemostasis.
• Risk factors for atony include uterine overdistension (multiple pregnancy, polyhydramnios, or macrosomia), prolonged labour, chorioamnionitis, and a history of previous postpartum haemorrhage.
• Genital tract trauma ("trauma") is a further important cause. It includes perineal, vaginal, cervical, or, less commonly, uterine trauma (including uterine rupture). It is particularly relevant after operative vaginal delivery, precipitate delivery, or a large infant.
• Retained placental tissue or membranes ("tissue") prevent adequate, sustained uterine contraction at the site of retention.
• The placenta accreta spectrum is a particularly high-risk cause of major haemorrhage and an important structural cause.
• Coagulopathy ("thrombin") is a further important, though less common, underlying or contributing cause. It may be pre-existing, such as a known inherited or acquired bleeding disorder.
• It may also be acquired during pregnancy or delivery, including disseminated intravascular coagulation secondary to placental abruption, amniotic fluid embolism, or severe pre-eclampsia.
• Secondary postpartum haemorrhage most commonly reflects retained products of conception or endometritis. It presents somewhat after the more immediately apparent primary haemorrhage causes.

• Excessive vaginal bleeding is the defining presenting feature. It may be a sudden, substantial volume loss or a more gradual, persistent loss that is cumulatively significant.
• Quantify blood loss carefully, accurately and continuously. Visual estimation alone has a well established tendency to substantially underestimate true blood loss.
• Signs of maternal haemodynamic compromise may develop: tachycardia, hypotension, and, in more severe cases, signs of shock.
• Healthy pregnant women can maintain apparently normal vital signs despite substantial blood loss for a period, because of the physiological blood volume expansion of pregnancy.
• Relying on vital sign changes alone risks delayed recognition of significant, ongoing haemorrhage. Quantify blood loss proactively and accurately rather than waiting for haemodynamic compromise to become apparent.
• Examination findings vary with the cause. A soft, poorly contracted ("boggy") uterus on abdominal palpation supports uterine atony.
• A well-contracted, firm uterus with ongoing significant bleeding suggests an alternative cause, including genital tract trauma. Examine the perineum, vagina, and cervix carefully and systematically to identify the site and source of bleeding.
• Secondary postpartum haemorrhage presents with vaginal bleeding beyond the initial twenty-four-hour postpartum period. Features of endometritis (fever and uterine tenderness) accompany it often, where infection is the underlying or contributing cause.

• Diagnosis is clinical, based on recognising excessive blood loss after delivery.
• Prompt, systematic assessment using the structured "four Ts" framework is essential. It rapidly identifies the underlying cause or causes and directly guides targeted, immediate management.
• Examine the uterus (assessing tone), the placenta and membranes after delivery (assessing completeness, and so the likelihood of retained tissue), and the genital tract (assessing for trauma).
• Assess coagulation status where coagulopathy is a clinical concern.
• In any significant postpartum haemorrhage, urgent laboratory assessment is essential, including full blood count, coagulation studies, and fibrinogen level, together with cross-matching of blood products. This supports ongoing monitoring and timely blood product support.
• Ultrasound may help identify retained products of conception, particularly in secondary postpartum haemorrhage.
• In acute primary postpartum haemorrhage, clinical assessment and, where indicated, examination under anaesthesia frequently are the more immediately relevant approach.

• Resuscitate and identify and treat the underlying cause simultaneously. Use a structured, systematic protocol with prompt escalation and involvement of senior obstetric, anaesthetic, and, where indicated, haematology expertise.
• Immediate, effective communication and coordination are essential in this time-critical obstetric emergency.
• For uterine atony, the commonest cause, initial management is uterine massage (bimanual, where required, for more significant atony) with prompt uterotonic agents.
• Oxytocin is standard first-line treatment. Ergometrine, carboprost, and misoprostol are additional or alternative uterotonic agents, used according to clinical response and contraindications. Avoid ergometrine in women with significant hypertension.
• If uterotonics and massage fail to achieve satisfactory haemostasis, escalate to balloon tamponade. A specifically designed intrauterine balloon device provides direct, tamponading pressure against the placental bed.
• If this is inadequate, proceed to surgery: compression suture techniques (such as the B-Lynch suture), and uterine artery or, where required, internal iliac artery ligation.
• Emergency hysterectomy is the definitive, life-saving measure for haemorrhage not controlled by these less invasive approaches.
• Interventional radiological techniques, including uterine artery embolisation, are a further option in appropriately selected, haemodynamically stable patients with access to the expertise and facility. They offer the potential advantage of preserving the uterus, and so future fertility, compared with hysterectomy.
• Promptly explore and remove any retained placental tissue. Carefully and systematically repair any genital tract trauma. These address the causes identified by the "four Ts" assessment.
• Give structured blood product support, following an established massive transfusion protocol where haemorrhage is severe, and correct any identified coagulopathy. This is an integral part of management alongside cause-directed treatment.
• Active management of the third stage of labour, comprising prophylactic uterotonic administration, is the primary preventive strategy. Clear evidence shows it substantially reduces the incidence of postpartum haemorrhage.
• Monitor postoperatively and ongoing. Where significant haemorrhage and intervention (including hysterectomy) have occurred, offer psychological support and, where relevant, discuss the implications for future fertility.