What are the stages of labor?

From the Guidelines

Labor is divided into three distinct stages: the first stage involving cervical dilation up to 10 cm, the second stage involving the descent and delivery of the fetus, and the third stage involving the delivery of the placenta. The first stage of labor, as described in the study by 1, involves the gradual shortening and dilatation of the cervix up to 10 cm, which may take up to 36 hours in primiparous women and is shorter in those who have previously had children. Key characteristics of each stage include:

• First stage:
  • Gradual cervical dilation up to 10 cm
  • Duration: up to 36 hours in primiparous women, shorter in multiparous women
• Second stage:
  • Descent of the fetus through the birth canal and delivery
  • Duration: between 30 minutes and 2 hours
• Third stage:
  • Delivery of the placenta
  • Duration: up to 1 hour if not induced, as noted in the study by 1. Understanding these stages is crucial for expectant parents to prepare mentally and physically for childbirth, although individual experiences may vary widely in duration and intensity.

From the Research

Stages of Labor

The stages of labor are typically divided into three distinct phases: the first, second, and third stage of labor 2. However, older textbooks recognized five phases, which included:

• The period between the onset of labor-like activity and the start of progressive cervical dilatation
• The phase of progressive cervical dilatation
• The descent of the fetal head to the pelvic floor
• The active expulsion of the baby
• The period between birth and delivery of the placenta, also known as the third stage of labor

First Stage of Labor

The first stage of labor is further subdivided into latent and active phases 2. The latent phase is characterized by the onset of labor-like activity, while the active phase is marked by progressive cervical dilatation.

Second Stage of Labor

The second stage of labor is also subdivided into phases, including:

• The period before the start of maternal expulsive efforts
• The period after the start of maternal expulsive efforts
• Some studies have identified three behavioral phases in the second stage of labor, which can be identified by changes in behavior over the progression of the second stage 3

Third Stage of Labor

The third stage of labor, also known as the placental stage, is the period between birth and delivery of the placenta 2. This stage is critical for preventing postpartum hemorrhage and ensuring maternal and fetal well-being.

Key Factors Affecting Labor

Several factors can affect the progression and outcome of labor, including:

• Labor onset, which can be spontaneous or induced 4
• The use of oxytocin to strengthen uterine contractions 4, 5, 6
• The use of epidural anesthesia for pain management 4, 5
• The duration of labor, which can impact maternal and fetal outcomes 4