Open Access Highly Accessed Research article

Causes of death and associated conditions (Codac) – a utilitarian approach to the classification of perinatal deaths

J Frederik Frøen12*, Halit Pinar3, Vicki Flenady45, Safiah Bahrin6, Adrian Charles7, Lawrence Chauke8, Katie Day5, Charles W Duke9, Fabio Facchinetti10, Ruth C Fretts2, Glenn Gardener4, Kristen Gilshenan5, Sanne J Gordijn11, Adrienne Gordon12, Grace Guyon13, Catherine Harrison14, Rachel Koshy6, Robert C Pattinson15, Karin Petersson16, Laurie Russell17, Eli Saastad118, Gordon CS Smith19 and Rozbeh Torabi3

Author Affiliations

1 Department of Genes and Environment, Division of Epidemiology, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, N-0403 Oslo, Norway

2 Department of Obstetrics, Gynecology and Reproductive Biology, Harvard Medical School, Boston, MA, USA

3 Department of Pathology and Laboratory Medicine, Brown University Medical School, Providence, RI, USA

4 Department of Obstetrics and Gynaecology, University of Queensland, Mater Mothers' Hospital, Brisbane, Australia

5 Mater Mothers' Research Centre, Mater Health Services, Brisbane, Australia

6 Division of Family Health Development, Ministry of Health Malaysia, Putrajaya, Malaysia

7 Department of Paediatric and Perinatal Pathology, King Edward Memorial Hospital, Perth, Australia

8 Department of Gynaecology and Obstetrics, Kalafong Academic Hospital, Pretoria, South Africa

9 National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA, USA

10 Unit of Psychobiology of Reproduction-UCADH, Mother-Infant Department, Università di Modena e Reggio Emilia, Modena, Italy

11 Department of Obstetrics and Gynaecology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands

12 Department of Neonatal Medicine, Royal Prince Alfred Hospital, Sydney, Australia

13 Alberta Perinatal Health Program, Edmonton, Canada

14 Telethon Institute for Child Health Research, Centre for Child Health Research, The University of Western Australia, Subiaco, Australia

15 Department of Obstetrics and Gynaecology, University of Pretoria School of Medicine, Pretoria, South Africa

16 Department of Obstetrics, Karolinska University Hospital, Stockholm, Sweden

17 Division of Anatomical Pathology, Department of Laboratory Medicine & Pathology, University of Alberta Hospitals, University of Alberta, Edmonton, Canada

18 Department of Midwifery, Faculty of Nursing Education, Akershus University College, Lillestrøm, Norway

19 Department of Obstetrics & Gynaecology, School of Clinical Medicine, University of Cambridge, Cambridge, UK

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BMC Pregnancy and Childbirth 2009, 9:22  doi:10.1186/1471-2393-9-22

Published: 10 June 2009


A carefully classified dataset of perinatal mortality will retain the most significant information on the causes of death. Such information is needed for health care policy development, surveillance and international comparisons, clinical services and research. For comparability purposes, we propose a classification system that could serve all these needs, and be applicable in both developing and developed countries. It is developed to adhere to basic concepts of underlying cause in the International Classification of Diseases (ICD), although gaps in ICD prevent classification of perinatal deaths solely on existing ICD codes.

We tested the Causes of Death and Associated Conditions (Codac) classification for perinatal deaths in seven populations, including two developing country settings. We identified areas of potential improvements in the ability to retain existing information, ease of use and inter-rater agreement. After revisions to address these issues we propose Version II of Codac with detailed coding instructions.

The ten main categories of Codac consist of three key contributors to global perinatal mortality (intrapartum events, infections and congenital anomalies), two crucial aspects of perinatal mortality (unknown causes of death and termination of pregnancy), a clear distinction of conditions relevant only to the neonatal period and the remaining conditions are arranged in the four anatomical compartments (fetal, cord, placental and maternal).

For more detail there are 94 subcategories, further specified in 577 categories in the full version. Codac is designed to accommodate both the main cause of death as well as two associated conditions. We suggest reporting not only the main cause of death, but also the associated relevant conditions so that scenarios of combined conditions and events are captured.

The appropriately applied Codac system promises to better manage information on causes of perinatal deaths, the conditions associated with them, and the most common clinical scenarios for future study and comparisons.