JMIR Publications

ABSTRACT

Background:

Stillbirths and neonatal deaths have long been imperfectly classified and recorded worldwide. In Hong Kong, the current coding system is deficient (> 90% cases with unknown causes) in providing the diagnoses of perinatal mortality cases.

Objective:

The objective of this study was to apply the ICD-PM system into existing perinatal death data. Further, the aim was to assess whether there was any change in the classifications of perinatal deaths compared to existing classification system and identify any areas in which future interventions can be made.

Methods:

We applied the ICD-PM (with ICD-10) coding system to existing perinatal death data in Kwong Wah Hospital, Hong Kong to improve diagnostic classification. The study included stillbirths (SB) (after 24 weeks gestation) and neonatal deaths (NND) (from birth to 28 days). The retrospective data from 1st May 2012 to 30th April 2017 (5 years) were recoded by the principal investigator (HML) applying ICD-PM, then validated by an overseas expert (EA) after reviewing the detailed case summaries. The prospective application of ICD-PM from 1st May 2017 to 30th April 2019 was performed during the monthly multidisciplinary perinatal meetings, and then also validated by EA for agreement.

Results:

We analyzed the data of 34,920 deliveries. One hundred and nineteen cases were included for analysis (92 stillbirths and 27 NNDs). The overall agreement with EA of our coding using ICD-PM was 93.2%; 91.8% for the 5 years retrospective codings (n=85) and 97.1% for the 2 years prospective codings (n=34) (p=0.437). After the application of ICD-PM, the overall proportion of “unknown” causes of perinatal mortality dropped from 41 cases (34.5%) to 12 cases (10.1%) (p<0.001).

Conclusions:

Using the ICD-PM would lead to a better classification of perinatal deaths, reduce the proportion of unknown diagnoses, as well as to clearly link the maternal conditions with these perinatal deaths.