Reclassification of unexplained stillbirths using clinical practice guidelines

Abstract

Background: Twenty-eight per cent of stillbirths in Australia remain unexplained. A clinical practice guideline (CPG) produced by the Perinatal Society of Australia and New Zealand (PSANZ) Perinatal Mortality Special Interest Group is in use to assist clinicians in the investigation and audit of perinatal deaths. Aims: To describe in a tertiary hospital using the PSANZ stillbirth investigation guidelines: (i) the distribution and classification of stillbirths, and (ii) the compliance with suggested stillbirth core investigations. Methods: Retrospective cohort of all stillbirths delivered between November 2005 and March 2008. Stillbirths were defined as no sign of life on delivery at >= 20 weeks gestation or 400 g birthweight if gestation is unknown. Data were collected via the hospital Perinatal Mortality Audit Committee (PMAC). Cause of death was classified by the PSANZ Perinatal Death Classification. Results: There were 86 stillbirths (rate 7.2 per 1000 births). The percentage of unexplained stillbirths was 34% and 13% before and after CPG investigations, respectively. Unexplained stillbirths had the highest compliance with the recommended investigations. The initial cause of death documented on the death certificate was changed by the PMAC in 19 cases. The investigations most likely to prompt a change in the cause of death classification were autopsy and placental pathology. Conclusions: The percentage of unexplained stillbirths is lower than the national average in a hospital using the Perinatal Mortality Audit Guidelines. However, overall compliance is low, suggesting a targeted approach to investigation is used by clinicians despite a policy that aims to be non-selective. Autopsy and placental examination are the most useful investigations in assisting formal classification of cause of death.