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Summary

Introduction

• Haemorrhage—antepartum, intrapartum and postpartum—remains the leading cause of maternal mortality worldwide, accounting for approximately 27% of maternal deaths, with proportions exceeding 30% in sub‐Saharan Africa and South Asia.
• Global incidence of postpartum haemorrhage (blood loss > 500 mL after vaginal delivery or > 1 000 mL after caesarean delivery) is 10.8%, with severe cases (> 1 000 mL) in 2.8% of deliveries.

General Anaesthetic Considerations for Placental Pathology

Pre‐operative Assessment and Preparation

• Full blood count, coagulation profile, group and save, cross‐match (minimum 4 units).
• Ensure availability of cell salvage, rapid infusers and blood‐warming devices.
• Optimise antenatal anaemia with intravenous iron or erythropoietin where indicated.

Pharmacological Haemostatic Strategies

• Tranexamic acid (TXA): 1 g IV infusion over 10 minutes within 3 hours of bleeding onset; repeat 1 g if bleeding persists after 30 minutes (WOMAN trial).

Choice of Anaesthetic Technique

• Neuraxial anaesthesia (spinal or combined spinal–epidural) is preferred for elective lower-segment caesarean section in placenta previa when coagulation parameters are normal:
  • Associated with ~20% lower estimated blood loss and ~30% fewer transfusions compared with general anaesthesia.
  • Conversion to general anaesthesia occurs in 10–20% of cases; counsel patients accordingly.
• General anaesthesia indicated for haemodynamic instability, ongoing massive haemorrhage or coagulopathy; rapid-sequence induction recommended

Antepartum Haemorrhage

• Bleeding after 20 weeks’ gestation and prior to delivery complicates ≈ 3–5% of pregnancies. Main causes:

1. Placenta previa
2. Placenta accreta spectrum
3. Placental abruption
4. Vasa praevia
5. Uterine rupture

Placenta Previa

Definitions and Classification

• Placenta previa: placental tissue reaches or covers the internal cervical os.
• Types:
  1. Major (complete coverage)
  2. Partial
  3. Marginal (within 2 cm of os)
  4. Low-lying (2–5 cm from os in the third trimester)

Risk Factors

• Previous caesarean section
• Advanced maternal age
• Multiparity
• Multiple gestation
• Smoking

Diagnosis and Monitoring

• Transabdominal/transvaginal ultrasound at 18–20 weeks; repeat at 32 weeks to assess placental migration.
• Digital vaginal examination contraindicated until placenta previa excluded

Management

• Elective caesarean at 37 weeks in a multidisciplinary centre.
• Neuraxial anaesthesia if stable (see Section 1.3).
• Prepare for massive transfusion, cell salvage and invasive monitoring.

Placenta Accreta Spectrum

Incidence and Risk Factors

• Incidence: ~0.4–0.9% of pregnancies; increasing with caesarean rates.
• Risk factors: prior uterine surgery (caesarean, myomectomy), multiparity, placenta previa.

Classification

1. Accreta: villi adhere to myometrium.
2. Increta: invasion into myometrium.
3. Percreta: penetration through uterine serosa ± adjacent organs.

Anaesthetic Considerations

• Planned delivery at 34–36 weeks in a centre of excellence with interventional radiology on standby.
• Neuraxial anaesthesia may be feasible if minimal anticipated blood loss.
• General anaesthesia with invasive arterial and central venous monitoring when massive haemorrhage is anticipated
• Adjuncts (balloon occlusion, cell salvage)

Placental Abruption

Incidence and Risk Factors

• Occurs in 0.6–1.2% of pregnancies.
• Risk factors: hypertension, trauma, pre-eclampsia, smoking, cocaine use, multiparity, short umbilical cord.

Clinical Presentation and Severity

• Vaginal bleeding ± uterine tenderness; may be concealed.
• Graded I–III (mild to severe) by volume of bleeding, uterine tone, maternal/fetal compromise

Management

• Immediate haemodynamic stabilisation and coagulation support.
• Emergency caesarean under general anaesthesia with rapid-sequence induction if maternal or fetal distress.
• Utilise massive transfusion protocols and point-of-care coagulation testing.

Uterine Rupture

Risk Factors and Presentation

• Risk factors: scarred uterus (prior caesarean/myomectomy), obstructed labour, oxytocin-induced hypertonus.
• Presentation: sudden abdominal pain, loss of fetal station, bleeding, shock.

Management

• Emergency laparotomy and delivery under general anaesthesia.
• Be prepared for hysterectomy and massive blood replacement.

Post Partum Haemorrhage

Definition

• Postpartum haemorrhage (PPH) is defined by the American College of Obstetricians and Gynecologists as cumulative blood loss ≥ 1000 mL or any blood loss accompanied by signs or symptoms of hypovolaemia within 24 hours of delivery, irrespective of mode of birth
• Severe PPH: blood loss > 2000 mL and/or transfusion of ≥ 4 packed red blood cells (PRBCs).
• Timing:
  • Primary (early): within 24 hours of delivery
  • Secondary (late): > 24 hours and up to 12 weeks postpartum

Pathogenesis (the “Four T’s”)

1. Tissue
   • Retained placental fragments prevent adequate myometrial contraction and vessel compression.
   • Risk factors: manual removal of placenta, placenta accreta spectrum, uterine atony.
2. Thrombin (coagulopathy)
   • Consumptive coagulopathy (e.g. disseminated intravascular coagulation), pre‐existing bleeding disorders.
   • Obstetric triggers: placental abruption, amniotic fluid embolism, pre‐eclampsia.
3. Tone (uterine atony)
   • Most common cause (≈ 70% of PPH).
   • Predisposing factors: over-distension (multiple gestation, polyhydramnios, macrosomia), prolonged or augmented labour (oxytocin), general anaesthesia.
4. Trauma
   • Genital tract lacerations, uterine rupture, instrumental delivery, caesarean section.

• Additional risk factors include maternal age > 34 years, multiparity, fibroids, smoking, chorioamnionitis, and hypertensive disorders of pregnancy.

Clinical Recognition

• Visual estimation of blood loss underestimates actual loss by up to 50%.
• Rule of 30 (≈ 30% of maternal blood volume lost):
  • Haemoglobin ↓ 30%
  • Urine output < 30 mL/h
  • Heart rate ↑ 30 bpm
  • Systolic blood pressure ↓ 30 mmHg
  • Respiratory rate > 30 breaths/min
• Shock index (heart rate ÷ systolic blood pressure)
  • Normal ≤ 0.9; > 1.7 predicts need for ≥ 4 units PRBCs, hysterectomy, ICU admission, mortality

Management Algorithm

Step 1: Recognition and Initial Resuscitation (≤ 30 min)

• Call for help: obstetric, anaesthetic and haematology teams.
• Monitoring: blood pressure, heart rate, oxygen saturation, urine output, shock index.
• Establish two large-bore IV lines; send for full blood count, coagulation screen, group and cross-match.
• Send fixed-ratio red cell and plasma packs via massive transfusion protocol (MTP).
• Uterine massage and manual removal of retained tissue if indicated.

Step 2: Uterotonic Agents

• Administer sequentially if tone remains inadequate:

1. Oxytocin: 10–30 IU in 1 L crystalloid infusion (slow infusion; bolus avoided).
2. Ergometrine (methylergometrine) 0.2 mg IM (contraindicated if hypertension).
3. Carboprost (15-methyl prostaglandin F₂α) 250 µg IM every 15–30 min up to 2 mg total (contraindicated in asthma).
4. Misoprostol 800 µg rectally or sublingually.

Step 3: Haemostatic Support and Monitoring (next 30 min)

• Point-of-care coagulation testing (TEG/ROTEM) to guide component therapy:
  • Maintain fibrinogen ≥ 4 g/L (normal in term pregnancy 4.5–6 g/L).
  • Platelets ≥ 75 × 10⁹/L; PT/INR < 1.5 × normal; aPTT < 1.5 × normal.
• Tranexamic acid 1 g IV over 10 min; may repeat once.
• Fibrinogen concentrate or cryoprecipitate to restore fibrinogen.
• Consider recombinant factor VIIa only after correction of acidosis, hypothermia, thrombocytopenia and hypofibrinogenaemia.

Step 4: Mechanical and Surgical Interventions

• Mechanical tamponade: intrauterine balloon (e.g. Bakri).
• Compression sutures: B-Lynch or modified sutures.
• Arterial ligation: uterine or internal iliac arteries.
• Hysterectomy for life-threatening haemorrhage unresponsive to conservative measures.
• Consider interventional radiology (embolisation) if stable and available.

Massive Transfusion Protocol

• Initial pack: 6 units O RhD-negative red cells, 4 units AB plasma, 1 apheresis platelet unit.
• Ratio-based vs goal-directed: current evidence favours point-of-care–guided therapy to minimise volume overload and TRALI.

Blood Conservation Strategies

• Antepartum: screen and treat iron-deficiency anaemia (target Hb ≥ 11 g/dL).
• Postpartum: consider IV iron before transfusion if stable.
• Cell salvage: safe in high-risk caesarean sections with leukocyte filtration and appropriate Rho(D) immunoglobulin.

Cyklokapron (Tranexamic Acid) in Obstetric Cesarean Section – Evidence Summary

Category	Details / Evidence
Primary Use	Prophylactic TXA (Cyklokapron) at 1 g IV before skin incision, alongside uterotonic therapy in cesarean delivery.
Effect on Blood Loss	Meta-analysis of ~50 RCTs showed reduced risk of blood loss > 1000 mL, lower mean blood loss, reduced transfusion needs, and less drop in hemoglobin, with greater benefit in high‑risk patients.
Timing of Administration	Benefit seen when TXA given before skin incision; no clear benefit if administered after cord clamping.
Maternal Mortality / Clinical Endpoints	Large trials (e.g. TRAAP‑2, NIH-MFM Units Network) confirmed reduced blood loss but no significant reduction in mortality or composite need-for-transfusion endpoints.
Safety & Thrombotic Risk	No significant increase in thromboembolic events overall; incidence remains low and statistically nonsignificant. Minor GI side effects may be modestly increased.
Evidence Quality	Moderate quality for high‑risk populations; overall evidence for low-risk populations rated low to very low.
Guideline Status	WHO and obstetric panels continue to support IV TXA for treatment of PPH. Prophylactic use in Cesarean section remains conditionally recommended, especially in high‑risk scenarios.
Outstanding Research	Ongoing trials (e.g. TRAAP‑VIA, I’M WOMAN) focusing on placenta previa, anaemic populations, and alternative TXA routes; results expected by late 2025.

Practice Conclusion

• Use of prophylactic IV TXA before incision in Cesarean delivery reduces hemorrhage and transfusion needs, with greater benefit in high-risk patients.
• The effect on clinical mortality or composite transfusion endpoints remains unproven.
• Thromboembolic risk is not significantly elevated under current dosing and use patterns.
• Optimal dosing, high-risk subgroup targeting, and administration timing continue to be refined in ongoing trials.

Links

• Polytrauma and haemorrhagic shock
• Point of Care Coagulation testing
• Clotting cascade
• Resus end targets in shock
• Obstetric emergencies
• Blood conservation in cardiac surgery
• Blood transfusions and conservation strategies
• Hypertension in pregnancy

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References:

1. Velde, M. V. d. and Varon, A. J. (2015). Obstetric hemorrhage. Current Opinion in Anaesthesiology, 28(2), 186-190. https://doi.org/10.1097/aco.0000000000000168
2. Van de Velde, Marca; Diez, Christianb; Varon, Albert J.b. Obstetric hemorrhage. Current Opinion in Anaesthesiology 28(2):p 186-190, April 2015. | DOI: 10.1097/ACO.0000000000000168
3. Butwick, Alexander J.a; Goodnough, Lawrence T.b,c. Transfusion and coagulation management in major obstetric hemorrhage. Current Opinion in Anaesthesiology 28(3):p 275-284, June 2015. | DOI: 10.1097/ACO.0000000000000180
4. The Calgary Guide to Understanding Disease. (2024). Retrieved June 5, 2024, from https://calgaryguide.ucalgary.ca/
5. FRCA Mind Maps. (2024). Retrieved June 5, 2024, from https://www.frcamindmaps.org/
6. Anesthesia Considerations. (2024). Retrieved June 5, 2024, from https://www.anesthesiaconsiderations.com/
7. PPH Image: Novice Anaesthesia. (2021). Infographics. Retrieved April 24, 2025, from https://www.gasnovice.com/infographics
8. Royal College of Obstetricians and Gynaecologists. Prevention and management of postpartum haemorrhage. Green-top Guideline No. 52. London: RCOG; 2017.
9. World Health Organization. WHO recommendations for the prevention and treatment of postpartum haemorrhage. Geneva: WHO; 2019.
10. Roberts I, Shakur H, Afenyi-Annan A, et al. The WOMAN Trial: tranexamic acid for the treatment of postpartum haemorrhage. Lancet. 2017;389(10084):2105–16.
11. Collins PW, et al. Early fibrinogen concentrate replacement in postpartum haemorrhage: a randomised controlled trial. Br J Anaesth. 2016;116(6):804–12.
12. Sentilhes L, Kayem G, Perrotin F, et al. Conservative management of severe postpartum haemorrhage using intrauterine balloon tamponade. Obstet Gynecol. 2016;127(4):613–19.

Summaries
Obs_Haemorrhage

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© 2025 Francois Uys. All Rights Reserved.

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