Causes of perinatal deaths in Australia: Slow progress in the preterm period

The majority of perinatal deaths occur in the preterm period; however, current approaches predominantly focus on prevention in the term period. Reducing perinatal deaths in the preterm period is, therefore, key to reducing the rates of perinatal death overall in Australia. The aim was to understand the classifications of causes of preterm stillbirth and neonatal death in Victoria over time and by gestation.

Retrospective study using state-wide, publicly available data. All births in Victoria between 2010 and 2018 included in the Victorian Perinatal Data Collection, excluding terminations of pregnancy for maternal psychosocial indications, were studied. Differences in causes of preterm perinatal mortality gestation group and over time were determined.

Out of 7977 perinatal deaths reported, 85.9% (n = 6849) were in the preterm period. The most common cause of preterm stillbirths was congenital anomalies (n = 1574, 29.8%), followed by unexplained antepartum deaths (n = 557, 14.2%). The most common cause of preterm neonatal death was spontaneous preterm birth (sPTB; n = 599, 38.2%), followed by congenital anomalies (n = 493, 31.4%). The rate of preterm stillbirths due to hypertension (-14.9% (95% CI -27.1% to -2.7%; P = 0.02)), maternal conditions (-24.1% (95% CI -44.2% to -4.0%; P = 0.03)) and those that were unexplained (-5.4% (95% CI -9.8% to -1.2%; P = 0.02)) decreased per annum between 2010 and 2018. All other classifications did not change significantly over time.

Prevention of congenital anomalies and sPTB is critical to reducing preterm perinatal mortality. Greater emphasis on understanding causes of preterm deaths through mortality investigations may reduce the proportion of those considered 'unexplained'.