CHAPTER 13 Primary PPH is defined as a blood loss of 500 ml or more within 24 hours of delivery and affects 3–5% of all deliveries. Massive PPH is clinically more important and may be life‐threatening. A reasonable definition of massive PPH is ‘loss of 50% of the blood volume within 3 hours of delivery’. Bleeding that is not so acute but continues at a rate of 150 ml/h or more, may also lead to unexpected maternal collapse. Bleeding that leads to haemodynamic instability would be another reasonable definition. Between 2013 and 2015 there were 21 deaths that were reported as being related to haemorrhage, and this group continues to be the second leading cause of death occurring within 42 days of the end of pregnancy (MBRRACE‐UK, 2017). The ‘four Ts’ is a simple tool to remind you of the common causes of primary PPH (RCOG, 2009a): The most common cause (70%) is poor uterine tone. Trauma accounts for 20% and may involve any part of the genital tract and includes tears of the vulva, vagina or cervix, as well as uterine rupture, which should be considered in cases of labour with a uterine scar (most commonly a previous caesarean section). Tissue cases (10%) could involve retention of part of, or the whole, placenta. Thrombin refers to the development of disseminated intravascular coagulation (DIC), where blood clotting mechanisms are deranged and signs include bleeding from venous puncture sites; blood that is passed does not form clots. Blood loss is notoriously difficult to estimate accurately and there is a tendency to underestimate (for estimating blood loss, see Figure 6.2). Maternal physiological changes include a significant increase in circulating volume, which means that during pregnancy (and immediately after delivery), women do not exhibit overt warning signs of imminent collapse. In pregnancy, pulse and blood pressure are usually maintained in the normal range until blood loss exceeds 1000 ml. Tachycardia, tachypnoea and a slight recordable fall in systolic BP occur with blood loss of 1000–1500 ml. A systolic BP below 80 mmHg, associated with worsening tachycardia, tachypnoea and altered mental state, usually indicates a PPH in excess of 1500 ml. If bleeding is more than expected it is recommended that early venous access is obtained with large‐bore cannulae. Although bleeding is obvious in most cases of major PPH, occasionally hypovolaemic shock can occur without overt bleeding. In these cases, consider haemorrhage that is ‘concealed’ – places where significant amounts of blood can accumulate include the paravaginal tissues (a haematoma of 2 litres or more may accumulate in the tissue space) and intra‐abdominally (if there has been a uterine rupture). This is bleeding that occurs between 24 hours and 6 weeks post‐delivery. It most commonly occurs between the 5th and 10th day. This can be defined as: Vulval – rupture of a vulval varix (varicose vein) or associated with perineal trauma. This can occur with a normal delivery and apparently intact perineum. An obvious painful swelling will be seen on one side of the vulva. It may present with severe buttock pain. Vaginal – blood can accumulate in the space on either side of the vagina. There may or may not be pain and bleeding. This is a large potential space where several litres of blood may accumulate. Usually, nothing is visible on inspection of the vulva and the woman will eventually present with shock. Broad ligament – the level of shock is out of proportion to the amount of blood loss seen.
Emergencies after delivery
13.1 Primary postpartum haemorrhage
Definition
Risk factors
Diagnosis
Pre‐hospital management
13.2 Secondary postpartum haemorrhage
Definition
Risk factors
Diagnosis
Pre‐hospital management
13.3 Trauma to the birth canal
Definition
Perineal trauma
Cervical trauma
Uterine trauma
Haematomas