The WHO application of the tenth edition of the International Classification of Diseases (ICD-10) to deaths during the perinatal period (ICD Perinatal Mortality, ICD-PM) captures the essential characteristics of the mother-baby dyad that contribute to perinatal deaths. We compare the capture of maternal conditions in the existing ICD-PM with the maternal codes from the WHO application of ICD-10 to deaths during pregnancy, childbirth, and the puerperium (ICD Maternal Mortality, ICD-MM) to explore potential benefits in the quality of data received.

Retrospective application of ICD-PM.

South Africa and the UK.

Perinatal death databases.

The maternal conditions were classified using the ICD-PM groupings for maternal condition in perinatal death, and then mapped to the ICD-MM groupings of maternal conditions.

Main maternal conditions in perinatal deaths.

We reviewed 9661 perinatal deaths. The largest group (4766 cases, 49.3%) in both classifications captures deaths where there was no contributing maternal condition. Each of the other ICD-PM groups map to between three and six ICD-MM groups. If the cases in each ICD-PM group are re-coded using ICD-MM, each group becomes multiple, more specific groups. For example, the 712 cases in group M4 in ICD-PM become 14 different and more specific main disease categories when the ICD-MM is applied instead.

As we move towards ICD-11, the use of the more specific, applicable, and relevant codes outlined in ICD-MM for both maternal deaths and the maternal condition at the time of a perinatal death would be preferable, and would provide important additional information about perinatal deaths.

Improving the capture of maternal conditions in perinatal deaths provides important actionable information.