Fundamental classification of perinatal death validation of a new classification system of perinatal death

Abstract Objective : To validate a newly introduced classification system for the registration of perinatal mortality. Design : Descriptive. Setting : Dutch Healthcare region Delft-Westland-Oostland (DWO). Material and methods : In a 10-years period (1983–1992), all cases of perinatal death with a birthweight above 500 g ( n =239) were included into the study. Six assessors: four gynaecologists and two paediatricians were asked to classify all cases using a classification model proposed by the authors. This model is based on the underlying cause of death using simple principles of obstetrical and neonatal pathology: birth trauma, infection, placenta or cord pathology, pathology of immune tolerance of mother and fetus, congenital malformation of the fetus and complications of a pre-viable delivery. Therefore, we used the term fundamental classification. The six assessors worked independently of each other in classifying all cases of perinatal death, were not involved in the original development of the system and were unaware of the results of the classification of their colleagues. Agreement beyond chance between assessors was calculated using kappa’s coefficient for multiple observers and multiple test results. Results : Overall kappa was 0.70 (95% confidence interval (C.I.) 0.68–0.72). Reproducibility was poor for the categories trauma and unclassifiable, fair for the categories infections and placental/cord pathology, and very good to excellent for the categories maternal immune system pathology, congenital malformations and complications of prematurity. Conclusions : The proposed system showed a good level of agreement and appeared to be simply applicable. It offers a good insight in the underlying cause of death with the possibility for recognising preventive factors in future pregnancies and will enable (inter)national comparisons in causes of perinatal death. A reliable uniform registration of perinatal death based on the underlying causes should be the basis for improvement of the quality of perinatal care.