Primary Post-Partum Haemorrhage

Aetiology and Risk Factors:

The causes for primary post-partum haemorrhage can be broadly categorised by the 4 T’s – tone, tissue, trauma and thrombin.

Tone

‘Tone’ refers to uterine atony, which is the most common cause of primary post-partum haemorrhage. This is where the uterus fails to contract adequately following delivery, due to a lack of tone in the uterine muscle.

The risk factors for uterine atony include:

• Maternal profile: Age >40, BMI > 35, Asian ethnicity.
• Uterine over-distension – multiple pregnancy, polyhydramnios, fetal macrosomia.
• Labour – induction, prolonged (>12 hours).
• Placental problems – placenta praevia, placental abruption, previous PPH.

Tissue

‘Tissue’ refers to retention of placental tissue – which prevents the uterus from contracting. It is the second most common cause of 1° PPH

Trauma

This refers to damage sustained to the reproductive tract during delivery (e.g. vaginal tears, cervical tears). Risk factors include:

• Instrumental vaginal deliveries (forceps or ventouse)
• Episiotomy
• C-section

Thrombin

‘Thrombin’ refers to coagulopathies and vascular abnormalities which increase the risk of primary post-partum haemorrhage:

• Vascular – Placental abruption, hypertension, pre-eclampsia.
• Coagulopathies – von Willebrand’s disease, haemophilia A/B, ITP or acquired coagulopathy i.e. DIC, HELLP.

By OpenStax College [CC BY 3.0], via Wikimedia Commons

Fig 1
Placenta praevia, where the placenta is inserted into the lower uterine segment. It is an important risk factor for post-partum haemorrhage.

Clinical Features

The main feature of a post-partum haemorrhage is bleeding from the vagina.

If there is substantial blood loss, the patient may complain of dizziness, palpitations, and shortness of breath.

On Examination:

• General examination may reveal haemodynamic instability with tachypnoea, prolonged capillary refill time, tachycardia, and hypotension.
• Abdominal examination may show signs of uterine rupture i.e. palpation of fetal parts as it moves into the abdomen from the uterus.
• Speculum examination may reveal sites of local trauma causing bleeding.
• Examine the placenta to ensure that the placenta is complete (a missing cotyledon or ragged membranes could both cause a PPH).

By תמרה דהן - דולה [CC BY-SA 3.0], via Wikimedia Commons

Fig 2
A complete placenta. In the assessment of post-partum haemorrhage, the placenta should be examined.

Investigations

The initial laboratory tests in primary post-partum haemorrhage include:

• Full blood count
• Cross match 4-6 units of blood
• Coagulation profile
• Urea and Electrolytes
• Liver function tests

Management

The management of primary post-partum haemorrhage should include the simultaneous delivery of TRIM:

• Teamwork (Immediate Management)
• Resuscitation (Immediate Management)
• Investigations and Monitoring (Immediate Management)
• Measures to arrest bleeding (Definitive Management)

Immediate Management

• Teamwork – Involve appropriate colleagues for minor and major PPH, including the midwife in charge and midwives, obstetricians, anaesthetists, blood bank, clinical haematologist and porters. Communication between the team, and diligent documentation is vital.
• Investigations and Monitoring – Investigations as above. Monitoring should include RR, O2 sats, HR, BP, temperature every 15 mins. Consider catheterisation and insertion of a central venous line.

Definitive Management

The definitive treatment for primary post-partum haemorrhage is largely dependent on the underlying cause:

Uterine Atony

• Bimanual compression to stimulate uterine contraction – insert a gloved hand into the vagina, then form a fist insider the anterior fornix to compress the anterior uterine wall and the other hand applies pressure on the abdomen at the posterior aspect of the uterus (ensure the bladder is emptied by catheterisation).
• Pharmacological measures (Table 1) – act to increase uterine myometrial contraction.
• Surgical measures – intrauterine balloon tamponade, haemostatic suture around uterus (e.g. B-lynch), bilateral uterine or internal iliac artery ligation, hysterectomy (as a last resort).

By Christopher Balogun-Lynch and Tahira Aziz Javaid [CC BY 3.0]

Fig 3
Management of PPH; (a) Bimanual compression, (b) Balloon tamponade.

Trauma

Primary repair of laceration, if uterine rupture: laparotomy and repair or hysterectomy.

Tissue

Administer IV Oxytocin, manual removal of placenta with regional or general anaesthetic, and prophylactic antibiotics in theatre. Start IV Oxytocin infusion after removal.

Thrombin

Correct any coagulation abnormalities with blood products under the advice of the haematology team.

Prevention

Active management of the 3^rd stage of labour routinely reduces PPH risk by 60%:

• Women delivering vaginally should be administered 5-10 units of IM Oxytocin prophylactically.
• Women delivering via C-section should be administered 5 units of IV Oxytocin