Long latent phase of labour

Created Oct 2012
Reviewed Dec 2019


How should ‘long latent phase of labour’ be coded when it meets the ACS 0002 Additional diagnoses criteria?

Some regard the ‘latent phase’ as a part of stage 1 of labour and as a result would code it to O63.0 Prolonged first stage (of labour).  Others regard the beginning of stage 1 of labour as ‘established labour’ and only include the active phase.  This would leave us with O62.9 Abnormality of forces of labour, unspecified.


The first stage of labour is divided into two phases: latent and active.  

The latent phase is when the cervix thins and dilates from 0–4 cm, contractions may start and stop.  The latent phase can last hours, several days or weeks before active labour starts.

The active phase ‘established labour’ is when contractions are regular and the cervix dilates from 4–10 cm.

Clinical advice is that ‘long latent phase of labour’ could be a statement or a diagnosis.  Causes for a long latent phase can include diagnoses such as, failure of cervical dilation, atonic uterus and incoordinate uterine action.  In the cases where a specific cause is documented assign the appropriate code.  Where ‘long latent phase’ is documented without a cause and it meets the ACS 0002 Additional diagnoses criteria assign the diagnosis code O62.9 Abnormality of forces of labour, unspecified and use free text on the code description to specify long latent phase.

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