What are the alert and action lines on the partogram, and how do they guide management?

On the cervicogram, the alert line is drawn from the point of assessment in the active phase at the expected rate of 1 cm/hour (the line of expected progress). The action line is drawn 4 hours parallel and to the right of the alert line (the limit of acceptable progress).

If dilatation crosses to the right of the alert line, close monitoring is needed; crossing the action line indicates intervention (the type depending on the cause).

Clinical relevance. The alert and action lines objectively identify slow labour and trigger monitoring then intervention.

More Detail

Alert and action lines

These lines on the partogram identify abnormally slow labour and trigger management.

The alert line

• Drawn on the cervicogram from the point of assessment of cervical dilatation in the active phase, at a rate of 1 cm/hour.
• Represents the expected line of progress.

The action line

• Drawn 4 hours parallel and to the right of the alert line.
• Represents the acceptable limit of progress.

How they guide management

• If cervical dilatation falls to the right of the alert line - close monitoring is necessary (progress is slower than expected).
• If it falls to the right of the action line - intervention is indicated.
• The type of intervention depends on the clinical condition - e.g. augmentation (for inadequate contractions, after excluding obstruction) or caesarean (for cephalo-pelvic disproportion/malpresentation/failed augmentation).