What it is

A descriptive labour progress reference tool — not a predictive model. It displays published P5, P50, and P95 duration percentiles for the active first stage and second stage of labour in low-risk women, and shows where an entered elapsed time falls in that reference distribution. The data is stratified by parity, cervical dilatation at the start of timing, and epidural status.

How to use

• Select parity: Nulliparous or Parous.
• Select stage and starting dilatation (first stage: 4, 5, or 6 cm; second stage).
• Select epidural status (where applicable).
• Enter elapsed time in hours and minutes.
• The reference percentiles and the position of the entered time update immediately.

What to expect

P5, P50, and P95 reference values for the selected combination (in hours:minutes). The entered time is placed on this scale and its approximate percentile position is shown. An alert is raised if elapsed time is at or above the 90th percentile. This is a reference comparison only — decisions about intervention should be based on overall clinical assessment, not duration alone.

Evidence basis