Third Stage of Labor: Placental Delivery and Management

The third stage of labour is the interval from the birth of the baby to the delivery of the placenta and membranes. Its care is a focus of midwifery practice because the way it is managed influences the risk of postpartum haemorrhage, one of the leading causes of maternal mortality worldwide.

Definition

The third stage of labour is the period from delivery of the infant until expulsion of the placenta and membranes; its management refers to the care provided during this interval to support placental delivery and reduce the risk of postpartum haemorrhage.

Scope

The entry covers the physiology of placental separation and delivery, the contrast between active and expectant (physiological) management of the third stage, the components of active management (a prophylactic uterotonic, cord management, and controlled cord traction), and the timing of cord clamping. It is a reference overview and does not give dosing or individualised management instructions.

Core questions

• What physiological processes lead to placental separation and delivery?
• How do active and expectant management of the third stage differ, and what are their effects?
• What are the components of active management and the evidence behind each?
• How does the timing of umbilical cord clamping affect maternal and neonatal outcomes?

Key concepts

• Placental separation and delivery
• Active management of the third stage
• Expectant (physiological) management
• Prophylactic uterotonics (e.g. oxytocin)
• Controlled cord traction
• Timing of umbilical cord clamping
• Postpartum haemorrhage prevention
• Uterine tone and involution

Mechanisms

After the baby is born, continued uterine contraction reduces the placental attachment site, causing the placenta to shear off the uterine wall and be expelled, while contraction of the myometrium compresses the spiral arteries to limit blood loss. Active management seeks to enhance and hasten this process: a prophylactic uterotonic such as oxytocin augments uterine contraction (Salati et al., 2019; Gallos et al., 2018), and controlled cord traction assists delivery of the separated placenta; together these reduce blood loss compared with expectant management (Begley et al., 2019). Cord clamping timing affects placental transfusion to the newborn (McDonald & Middleton, 2008).

Clinical relevance

Because postpartum haemorrhage is a major cause of maternal death, management of the third stage is a high-priority component of intrapartum care, and prophylactic uterotonics are widely recommended for prevention (WHO, 2018; Gallos et al., 2018). The choice between active and expectant management and the timing of cord clamping involve balancing maternal and neonatal considerations. This entry describes these approaches at a reference level and does not provide dosing or individualised guidance.

Epidemiology

Postpartum haemorrhage complicates a substantial minority of births and is a leading direct cause of maternal mortality, with the greatest burden in low-resource settings. The adoption of active management and prophylactic uterotonics, and practices around cord clamping, vary by setting and have shifted over time as evidence and guidance have evolved.

Evidence & guidelines

Cochrane systematic reviews show that active management reduces the risk of severe postpartum haemorrhage compared with expectant management, though with some trade-offs (Begley et al., 2019); prophylactic oxytocin reduces postpartum haemorrhage (Salati et al., 2019); and a network meta-analysis compares uterotonic agents for prevention (Gallos et al., 2018). Evidence on delayed (rather than early) cord clamping informs neonatal practice (McDonald & Middleton, 2008). WHO (2018) recommends a prophylactic uterotonic for all births.

History

Active management of the third stage was developed and promoted through the later twentieth century as a means of reducing postpartum haemorrhage, and large trials and systematic reviews subsequently clarified its benefits and the contribution of its individual components. The timing of cord clamping, long performed early, was re-examined as evidence accumulated favouring delayed clamping for neonatal benefit, leading to revised guidance.

Debates

Which components of active management drive its benefit?

Active management bundles a uterotonic, cord traction, and (historically) early cord clamping; research has worked to disentangle which components reduce haemorrhage, and early cord clamping has largely been dropped in favour of delayed clamping.

Seminal works

• begley-2019
• gallos-2018
• who-2018-intrapartum

Frequently asked questions

What is the difference between active and expectant management of the third stage?

Active management uses a prophylactic uterotonic, cord management, and controlled cord traction to hasten placental delivery and reduce blood loss, whereas expectant (physiological) management awaits spontaneous placental delivery without these interventions.

Why is third-stage management considered important?

Because postpartum haemorrhage is a leading cause of maternal death, and the way the third stage is managed — particularly the use of a prophylactic uterotonic — substantially affects the risk of severe bleeding.