A comparison of three classification systems for stillbirth

Background: Understanding the causes of perinatal death can provide relevant information to couples, caregivers, and society. Classification systems play a crucial role in identifying the most relevant conditions suggesting preventive measures for decreasing stillbirth (SB). In 2016 the International Classification of Disease to Deaths during the Perinatal Period (ICD-PM) was released with the aim to suggest a universally accepted classification. Methods: This is a prospective cohort study that enrolled all SBs occurred in Emilia–Romagna, from 2014 to 2017. We prospectively applied ReCoDe classification and retrospectively used Simplified CODAC classification and ICD-PM. The aim of this study is to compare different classification systems on a cohort of SBs, undergoing a comprehensive workup, to establish what classification minimizes rates of unexplained SB. Results: We registered 443 SBs. According to ReCoDe the largest category of SB was “placental insufficiency/infarction” (16.9%), followed by “abruptio placentae” (14.2%). Unexplained cases are 16.7%. Gestational age <37 weeks is less frequent in the group of women with unclassified SB (OR 0.50, OR95%CI [0.3–0.8]) against women with classified SB. Considering CODAC the two largest categories are “infarctions or thrombi” (16.3%) and “abruption or retro-placental haematoma” (15.1%), instead only 17.2% of cases remained unexplained. Conclusions: Comparing ReCoDe and CODAC we found no real difference in any category. ReCoDe and CODAC better underlines the primary cause of death. ICD-PM reveals to be easily applicable to clinical practice. ICD-PM has the lowest rate of unexplained SBs (9.3%) due to the structure itself and not to a deeper comprehension of death.