Primary Postpartum Haemorrhage

Postpartum haemorrhage is a major cause of maternal mortality. With respect to PPH:

Epidemiology and Risk Factors

In Australia, PPH:

  • Occurs at 6/1,000 deliveries
    Will likely ↑ over time:
    • ↑ maternal age
    • Conception following LUSCS
      ↑ percreta/accreta risk.
  • Has a mortality of 4/100,000 deliveries

Risk factors for PPH relate to the cause:

  • Atony
    • Maternal obesity
    • Maternal DM
    • Multiple pregnancy
    • Multiparity
    • Advanced maternal age
    • Prolonged labour
    • Augmented labour
    • Amniotic infection
    • Abnormal uterine anatomy
    • Uterine inversion
    • Macrosomia
  • Tissue
    • Abnormal placenta
    • Retained clot
    • Previous uterine surgery
    • Placenta praevia
    • Placenta accreta/percreta
  • Trauma
    • Precipitous delivery
    • Operative delivery
    • Foetal malposition
    • Multiparity
    • Previous uterine surgery
  • Thrombin
    • Hereditary disease
      • von Willebrand’s
      • Haemophilia
    • Acquired disease
      • ITTP
      • Pre-eclampsia
      • FDIU
      • Infection
      • Placental abruption
      • AFE
    • Therapeutic
      • Thromboprophylaxis

Pathophysiology

Aetiology

Causes grouped into the four T’s:

  • Atony
    Failure of uterine contraction.
    • Occurs in 10% of pregnancies
    • Causes 70% of PPH
  • Trauma
    Second most common cause, due to injury to:
    • Uterus
    • Cervix
    • Vagina
    • Perineum
  • Tissue
    Retained products of conception.
    • Third most common cause
    • Generally retained placental fragment
      May be related to placenta accreta.
  • Thrombin
    Coagulopathy.

Other causes:

  • Uterine inversion
    Where the fundus of the uterus begins to prolapse out of the cervix.
  • Uterine rupture
    Usually along a scar from previous caesarian or uterine surgery.

Clinical Features

Many features may be masked by the physiology of pregnancy, and blood loss is often underestimated.

Symptoms and signs of massive blood loss:

  • Tachycardia
  • Lightheadedness
  • Sweating
  • Pallor
  • Weakness
  • Hypotension
    Classically late sign in pregnant women.

Diagnostic Approach and DDx

PPH is due to either:

  • Tone
    • Uterine atony
  • Trauma
    • Uterine
    • Birth canal
  • Tissue
    • Retained placenta or membranes
  • Thrombin
    • Coaguolpathy
    • DIC

Investigations

Key investigations:

  • Group and Hold
  • Coagulation studies
    • Including D-dimer

Management

  • Haemostatic resuscitation
  • Manage uterine causes:
    • Tone
      Rubbing, uterotonics.
    • Trauma
      Operative repair.
    • Tissue
      Operative evacuation.
    • Thrombin
      Medical treatment of coagulopathy.

An empty, intact, contracted uterus will not bleed unless there is coagulopathy.

Resuscitation:

  • C
    • IV access and warm volume resuscitation
    • Haemostatic resuscitation
  • H
    • Consider TXA if <3 hours from birth

Specific therapy:

  • Pharmacological
    • Uterotonics
      Ensure active management of the third stage has been completed.
      • Oxytocin 10 units IV
        Commence infusion at 10 units/hr; usually 40 units in 1L of CSL/NS/D5W over 4 hours.
      • Ergometrine 0.25mg IM
        Can give a further 0.25mg IV; beware bronchospasm and hypertension. Up to a total of 1mg.
      • Metoclopramide 10mg IV
      • Carboprost 0.25mg IM
        Can repeat Q15 minutely, up to 2mg.
      • Consider misoprostol 1mg PR
      • Misoprostol
    • Uterine relaxation
      May be required in some circumstances, such as uterine inversion.
      • Volatile anaesthetics
      • GTN
  • Procedural
    • Deliver placenta
      • Controlled cord traction
        Examine for completeness.
    • Obstetric intervention
      • Uterine bleeding Escalating ladder of:
        • Uterine packing
          Up to 24 hours, cover with IV antibiotics and continue oxytocin infusion.
        • Uterine artery ligation
        • Internal iliac ligation
        • B-lynch suture
        • Hysterectomy
        • Interventional radiology
      • Birth canal injury
      • Retained products of conception
        • Requires operated delivery
        • May required uterine relaxation
  • Physical
    • Haemorrhage control
      • Bimanual uterine compression
      • Aorta compression
    • Uterine massage
      Rub up. Effective in most cases.

Supportive care:

  • E
    • Avoid hypothermia
  • H
    • Consider DDAVP 0.3μg/kg
      • Uraemia
        ≥20mmol/L.
      • von Willebrand’s disease
    • Consider factor VIIa in refractory haemorrhage or DIC

Disposition:

Preventative:

Anaesthetic Considerations

  • C
    • Haemodynamic stability
      • Key guide for resuscitation goals
  • D Anaesthetic techniques, in order of preference:
    * Epidural top-up * Spinal anaesthesia * Intravenous sedation
    May be appropriate in some instances. * General anaesthesia

Marginal and Ineffective Therapies

Complications

Prognosis

Key Studies

  • WOMAN (2017)
    • 20,060 women >16 with clinical PPH
    • Multicentre (193!), international, double-blinded, RCT
    • Powered for 0.75% ARR ↓ in death or hysterectomy at 42 days from 3% to 2.25%
    • TXA (1g) vs. placebo
      • Second dose administered for recurrent or ongoing bleeding
    • No difference in primary outcome (5.3% vs. 5.5%)
    • Secondary outcomes showed:
      • ↓ Death due to bleeding with TXA (1.5% vs. 1.9%, RR 0.85 (CI 0.65-1))
      • ↓ Death if TXA given in <3 hours of birth (1.2% vs. 1.7%), and ↑ death if after 3 hours (2.6% vs. 2.5%)

References

  1. RANZCOG. Management of Postpartum Haemorrhage. RANZCOG. 2017.
  2. Shakur H, Roberts I, Fawole B, et al. Effect of early tranexamic acid administration on mortality, hysterectomy, and other morbidities in women with post-partum haemorrhage (WOMAN): an international, randomised, double-blind, placebo-controlled trial. The Lancet. 2017;389(10084):2105-2116. doi:10.1016/S0140-6736(17)30638-4