Transfusion in Postpartum Haemorrhage

Postpartum haemorrhage is blood loss of 500 mL or more after vaginal birth, or 1000 mL or more after caesarean section, or any loss that causes signs of hypovolaemia. Major haemorrhage is 1000 mL or more with ongoing bleeding or shock. It is a leading cause of maternal death, mostly from delay in recognition, uterotonic treatment, tranexamic acid, fibrinogen replacement and surgical control. Obstetric haemorrhage differs from trauma because fibrinogen falls early and sharply.

Causes. The four Ts: tone (uterine atony, the commonest), trauma (tears, rupture, inversion), tissue (retained products, placenta accreta spectrum) and thrombin (coagulopathy: abruption, amniotic fluid embolism, sepsis, pre-eclampsia, HELLP syndrome and pre-existing disorders).

Risk context. Healthy pregnant women compensate until about 1500 mL of loss and then collapse suddenly. Visual blood loss estimation underestimates the loss.

Special groups. Women with anaemia, prior caesarean section, placenta praevia or accreta, multiple pregnancy, polyhydramnios, pre-eclampsia, bleeding disorders, sickle cell disease, and those who refuse blood. In East Africa, anaemia in pregnancy is common and reduces tolerance, home and health centre births delay care, and blood supply is limited, so early recognition, early referral and early use of uterotonics and tranexamic acid are decisive.

Recognition. Measure blood loss (collection drape or weighing). Shock index (heart rate divided by systolic pressure) of 0.9 or more suggests major haemorrhage in obstetric patients. Look for tachycardia, falling pressure, pallor, restlessness, oliguria and uterine tone.

Activation criteria. Loss over 1000 mL with ongoing bleeding, any signs of shock, or loss of 500 mL or more with continuing heavy bleeding or a high-risk woman. Activate the massive haemorrhage plan and call senior obstetric, anaesthetic, haematology and blood bank staff.

Laboratory. Send group and crossmatch, full blood count, coagulation screen and Clauss fibrinogen early, and use bedside clot observation or viscoelastic testing where available. A fibrinogen under 2 g/L predicts progression to severe haemorrhage.

Thresholds.

• Fibrinogen under 2 g/L: replace.

• Platelets under 50 x 10⁹/L with bleeding: transfuse.

• Prothrombin time or activated partial thromboplastin time over 1.5 times normal: plasma.

• Haemoglobin about 7 g/dL after control, with symptoms or ongoing risk in selected women.

Red flags. Atony not responding to two uterotonics, concealed bleeding (abruption, uterine rupture, broad ligament haematoma), coagulopathy, hypertensive disease and pulmonary oedema risk.

Stepwise management in parallel.

1. Call for help, lie the woman flat with a left lateral tilt if undelivered, give oxygen and secure two large bore intravenous lines.

2. Uterine massage, empty the bladder, and give uterotonics: oxytocin 5 to 10 units by slow intravenous injection or 10 units intramuscularly, followed by an infusion of about 40 units in 500 mL over 4 hours; ergometrine 0.25 mg intramuscularly (avoid in hypertension); carboprost 250 micrograms intramuscularly every 15 minutes up to 8 doses (avoid in asthma); misoprostol 800 micrograms sublingually when other drugs are unavailable.

3. Give tranexamic acid 1 g intravenously over 10 minutes within 3 hours of birth, and repeat once if bleeding continues after 30 minutes.

4. Examine for tears, retained tissue and inversion, and treat.

5. Balloon tamponade, compression sutures, uterine artery ligation, interventional radiology or hysterectomy if bleeding continues. Do not delay surgical control for resuscitation.

Blood and products.

• Red cells (or whole blood) early for shock or ongoing loss, with warmed products and rapid infusion.

• Fibrinogen early: cryoprecipitate two pools or fibrinogen concentrate 2 to 4 g as an empirical first dose, then directed by results, with a target over 2 g/L.

• Plasma 10 to 15 mL/kg for prolonged clotting times, and platelets for counts under 50 x 10⁹/L with bleeding.

• Calcium, warming, and avoidance of large crystalloid volumes.

• Cell salvage in major haemorrhage with leucocyte filtration, where available.

• RhD negative women with RhD positive babies receive anti-D immunoglobulin within 72 hours, with testing for foetomaternal haemorrhage.

Special groups.

• Pre-eclampsia: careful volume management, avoid ergometrine, and watch for pulmonary oedema.

• Sickle cell disease: avoid raising haemoglobin over 10 g/dL.

• Refusal of blood: all other measures, and early senior and ethics input.

• Anaemic women: lower reserve means earlier transfusion.

Monitoring. Continuous heart rate, blood pressure, oxygen saturation, urine output and uterine tone. Repeat haemoglobin, lactate, ionised calcium, platelets, coagulation and fibrinogen every 30 to 60 minutes during bleeding.

Complications. Hypovolaemic shock, disseminated intravascular coagulation, acute kidney injury, Sheehan syndrome, transfusion related lung injury and overload, hysterectomy and death.

Referral and escalation. Senior obstetrician, anaesthetist, haematologist, interventional radiologist and blood bank. Early transfer to a facility with surgical and blood capacity.

Disposition. After control, high dependency care, thromboprophylaxis once bleeding has settled, iron therapy for anaemia (oral or intravenous), and review of haemoglobin before discharge. Counsel on future pregnancy planning, and document all products.