An analysis of factors contributing to the risk of delivery-related perinatal death at term.

Death of a baby at the end of a normal pregnancy is a devastating complication for parents. The frequency of such complications due to problems in labour appears to be decreasing but the reasons are unknown. Rates of caesarean delivery have increased over the period of time where death rates have fallen. However, many other changes have taken place as well. This study aims to characterise the factors associated with the risk of death of the baby. Moreover, it seeks to determine why the rates have declined. The study will yield useful information on the factors which are associated with the risk of these events. It will also indicate whether rising rates of caesarean delivery may have contributed to the decline in the frequency of this outcome. The data collected in the Scottish Morbidity Record and the Scottish Stillbirth and Infant Death Enquiry will help address the research questions above.

Death of the infant as a consequence of intrapartum events is a devastating complication of term pregnancy. Much of obstetric intervention is aimed at preventing these events. Rates of death due to intrapartum complications have declined over recent years. This has been associated with rising rates of obstetric intervention, principally caesarean section. It is tempting to speculate that the two are related. During this period, risk factors for intrapartum still birth have also changed such as parity, age and birthweight. Analysis of the effects of increasing rates of obstetric intervention must take into account temporal changes in other factors which influence the risk of this event. This analysis requires a detailed analysis of very high quality data from large number of women. This includes detail data on perinatal death, which would be able to identify death due to a delivery related event. We have linked two data sources which has yielded a database which combines detailed information on the cause of perinatal death, detailed information on maternal, obstetric and service characteristics, with >99% population coverage for a period of 20 years. The two data sources are Scottish Morbidity Record (SMR2) and the Scottish Stillbirth and Infant Death Enquiry (SSBIDE).
Using this dataset we aim (1) to characterise the relationship between maternal, obstetric and service characteristics and the risk of delivery-related perinatal death at term, (2) to characterise the changes in delivery -related perinatal death over the 20 year period, and (3) to determine the effect, if any, of changes in these factors over the last 20 years on the rates of delivery-related perinatal death at term.
The outcomes of interest are intrapartum stillbirth and neonatal death due to delivery related event. The exposures of interest are fetal, maternal, obstetrics and service characteristics. Appropriate test for univariate comparisons will be performed. Crude and adjusted odd ratios will be obtained using logistics regression analysis. Regression techniques will employ robust standard errors to allow dependence of different births to the same mother. Missing data would be addressed. Goodness of fit will be assessed. The discrimination of the model will be assessed by the area under the receiver operating characteristic (ROC) curve.
This study will help determine the factors associated with delivery-related perinatal death and those which has influence it‘s rate. This would guide public health and obstetric intervention to further reduce the rate of delivery-related perinatal death.