Classification of causes and associated conditions for stillbirths and neonatal deaths

Abstract

Accurate and consistent classification of causes and associated conditions for perinatal deaths is essential to inform strategies to reduce the five million which occur globally each year. With the majority of deaths occurring in low- and middle-income countries (LMICs), their needs must be prioritised. The aim of this paper is to review the classification of perinatal death, the contemporary classification systems including the World Health Organization's International Classification of Diseases - Perinatal Mortality (ICD-PM), and next steps. During the period from 2009 to 2014, a total of 81 new or modified classification systems were identified with the majority developed in high-income countries (HICs). Structure, definitions and rules and therefore data on causes vary widely and implementation is suboptimal. Whereas system testing is limited, none appears ideal. Several systems result in a high proportion of unexplained stillbirths, prompting HICs to use more detailed systems that require data unavailable in low-income countries. Some systems appear to perform well across these different settings. ICD-PM addresses some shortcomings of ICD-10 for perinatal deaths, but important limitations remain, especially for stillbirths. A global approach to classification is needed and seems feasible. The new ICD-PM system is an important step forward and improvements will be enhanced by wide-scale use and evaluation. Implementation requires national-level support and dedicated resources. Future research should focus on implementation strategies and evaluation methods, defining placental pathologies, and ways to engage parents in the process.

A prospective review of perinatal mortality at Hospital Nacional Guido Valadares (HNGV)

“…The CODAC system was relatively easy to apply but approximately 45% of stillbirths in our study were ‘unknown’, only a slight improvement from 62% in Wilkins’ previous retrospective review . This is in contrast to studies undertaken in other LMIC settings using the CODAC classification system where the proportion of ‘unknown’ causes ranged from 8% to 25% . Some of the difficulties in classification in our study were related to: lack of accurate pregnancy dating limiting the detection of both growth‐restricted and post‐mature fetuses at risk of asphyxia; the lack of documented clinical history and a protocol for systematic examination of stillborn infants; and the limited capacity to confirm suspected diagnoses with investigations.…”

“…6 This is in contrast to studies undertaken in other LMIC settings using the CODAC classification system where the proportion of 'unknown' causes ranged from 8% to 25%. 10,25 Some of the difficulties in classification in our study were related to: lack of accurate pregnancy dating limiting the detection of both growth-restricted and post-mature fetuses at risk of asphyxia; the lack of documented clinical history and a protocol for systematic examination of stillborn infants; and the limited capacity to confirm suspected diagnoses with investigations. Compounding the latter is the lack of availability for histopathological examination of the placenta and autopsy of the fetus, primarily due to cultural taboos.…”

“…Accurate classification of causes and associated conditions for perinatal deaths may inform strategies to reduce mortality rates. This is particularly so with classification in LMICs which present many challenges: a substantial proportion of home births, limited antenatal care, uncertain gestational age and a lack of laboratory investigations, including autopsy …”

“…This is particularly so with classification in LMICs which present many challenges: a substantial proportion of home births, limited antenatal care, uncertain gestational age and a lack of laboratory investigations, including autopsy. 10,11 Globally, many different systems are used for classifying perinatal deaths. These differ in the number of causes recorded, whether antepartum and intrapartum stillbirths are differentiated, whether stillbirths and neonatal deaths are included concurrently and whether International Classification of Diseases (ICD) classification codes are utilised.…”

Risk of stillbirth, preterm delivery, and fetal growth restriction following exposure in a previous birth: systematic review and meta‐analysis

“…Stillbirth is the end point of multiple processes, including placental dysfunction. There are a number of stillbirth classification schemes in use that assign cause of death and/or factors contributing to stillbirth . Common causes or factors associated with stillbirth include congenital malformations, infection, hypoxia, fetal growth disorders, and PTB, and by identifying the cause of stillbirth, targeting interventions could be applied …”