A comparison of the Perinatal Society of Australia and New Zealand-Perinatal Death Classification system and relevant condition at death stillbirth classification systems.
BACKGROUND
Stillbirths comprise two-thirds of all perinatal mortality. A classification system with low 'unexplained' stillbirth rates is important when developing prevention strategies.


OBJECTIVE
This study aims to (i) determine whether the proportion of stillbirths classified as 'unexplained' is reduced, by using the relevant condition at death (ReCoDe) stillbirth classification system, compared with the Perinatal Society of Australia and New Zealand - Perinatal Death Classification (PSANZ-PDC) system; and (ii) compare the proportion of stillbirths attributed to fetal growth restriction and other causes by each system.


METHODS
The ReCoDe stillbirth classification system was applied to the National Women's Health's stillbirth database for years 2004-2007. The proportion of stillbirths classified as 'unexplained' and as a result of fetal growth restriction was compared between the ReCoDe and the PSANZ-PDC systems using the chi(2) test.


RESULTS
The proportion of stillbirths classified as unexplained was less with ReCoDe compared with PSANZ-PDC (8.5% (n = 26) vs 14.1% (n = 43) P = 0.04). The proportion with the primary cause attributed to fetal growth restriction was increased with ReCoDe compared with PSANZ-PDC (23.2% (n = 71) vs 8.2% (n = 25) P < 0.0001). However, 44.8% (n = 137) of all stillbirths were small for gestational age (birthweight < 10th customised centile). The most common primary cause or condition at death by both systems was congenital abnormalities.


CONCLUSIONS
The proportion of stillbirths classified as unexplained was less with ReCoDe compared with PSANZ-PDC but rates with either method were low compared with earlier classification systems. Fetal growth restriction was listed as the primary condition more commonly with ReCoDe compared with PSANZ-PDC because of different definitions.
Lu
Jye Ru
JR
National Women's Health, Auckland City Hospital, Level 9, Auckland City Hospital, 2, Park Road, Grafton, Auckland, New Zealand. jyeru@hotmail.com
McCowan
Lesley
L
D000328:Adult; D001315:Australia / Q000453:epidemiology; D002423:Cause of Death; D002965:Classification; D005260:Female; D005317:Fetal Growth Retardation / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D009520:New Zealand / Q000453:epidemiology; D010922:Placenta Diseases / Q000175:diagnosis / Q000453:epidemiology; D011247:Pregnancy; D050497:Stillbirth / Q000453:epidemiology*; D018875:Vocabulary, Controlled; D055815:Young Adult