Summary
Aims: This study aims to establish a complete and accurate set of Australian reference ranges to be used during the routine perinatal post-mortem examination. Eighteen routinely measured parameters will be analysed for each gestational age from 12 weeks to 42 weeks inclusive.
Methods: A retrospective review was performed of all perinatal and neonatal autopsies conducted at the Royal Women's Hospital (RWH), Melbourne, between 1 January 2001 and 31 December 2006. A total of 1116 post-mortem examination reports were analysed for this study. Established study design, technical and statistical methodologies were followed.
Results: Reference ranges comprising mean and standard deviation have been produced, together with the 5th, 50th and 95th percentiles for all parameters at each gestational age. Graphs demonstrating these data have been developed for each parameter.
Conclusion: This study has established a complete set of reference ranges for parameters measured at perinatal post-mortem examinations. As the sample population used is truly representative of the mixed immigrant population present in Australian society, the reference ranges and percentiles produced in this study will be valuable for all perinatal pathologists.
| Abbreviations | ||
| FDIU | = | fetal death in utero |
| GSD | = | geometric standard deviation |
| IUGR | = | intrauterine growth retardation |
| LMP | = | last menstrual period |
| RWH | = | Royal Women's Hospital, Melbourne |
| SD | = | standard deviation |
| Abbreviations | ||
| FDIU | = | fetal death in utero |
| GSD | = | geometric standard deviation |
| IUGR | = | intrauterine growth retardation |
| LMP | = | last menstrual period |
| RWH | = | Royal Women's Hospital, Melbourne |
| SD | = | standard deviation |
Notes
*The geometric standard deviation (GSD) serves a similar purpose to the (untransformed) standard deviation in that it can be used to calculate any percentile of the distribution of organ weights at any gestational age using tables of percentiles of the standard normal distribution (‘Z-values’), except that it operates as a multiplier rather than as an addition. For example, the 95th percentile is calculated as median × GSD1.645, whereas for organs which did not require logarithmic transformation, the 95th percentile is calculated as median + (1.645 × SD), noting that the mean and median coincide for organ weights following a normal distribution.