What are the key risk factors for postpartum haemorrhage that I should assess during antenatal care?

During antenatal care, several key risk factors for postpartum haemorrhage (PPH) should be assessed. Women with these antenatal risk factors should be advised to give birth in an obstetric unit where more emergency treatment options are available ¹.

• Previous obstetric history: This includes a previous PPH over 1,000 mL or one that required a blood transfusion ¹.
• Placental issues: Risk factors include placenta accreta spectrum, antepartum haemorrhage, placental abruption, and low-lying placenta ¹.
• Maternal health conditions: Pre-eclampsia is a significant risk factor ¹. A maternal haemoglobin level below 85 g/litre at the onset of labour also increases risk ¹.
• Maternal characteristics: A Body Mass Index (BMI) greater than 35 kg/m² is a risk factor ¹. Grand multiparity, defined as parity 4 or more, is also a factor ¹.
• Uterine conditions: Overdistention of the uterus, such as in multiple pregnancy or polyhydramnios, increases the risk ¹. Existing uterine abnormalities, like fibroids, are also relevant ¹.
• Medication use: Taking selective serotonin reuptake inhibitor (SSRI) or serotonin-noradrenaline reuptake inhibitor (SNRI) antidepressants in the month before birth may result in a small increased risk of PPH and should be considered in the bleeding and thrombotic risk assessment ¹.

If a woman has risk factors for PPH, these should be highlighted in her notes, and a care plan covering the third stage of labour should be agreed upon with her ¹.