An evaluation of classification systems for stillbirth

Abstract

BackgroundAudit and classification of stillbirths is an essential part of clinical practice and a crucial step towards stillbirth prevention. Due to the limitations of the ICD system and lack of an international approach to an acceptable solution, numerous disparate classification systems have emerged. We assessed the performance of six contemporary systems to inform the development of an internationally accepted approach.MethodsWe evaluated the following systems: Amended Aberdeen, Extended Wigglesworth; PSANZ-PDC, ReCoDe, Tulip and CODAC. Nine teams from 7 countries applied the classification systems to cohorts of stillbirths from their regions using 857 stillbirth cases. The main outcome measures were: the ability to retain the important information about the death using the InfoKeep rating; the ease of use according to the Ease rating (both measures used a five-point scale with a score <2 considered unsatisfactory); inter-observer agreement and the proportion of unexplained stillbirths. A randomly selected subset of 100 stillbirths was used to assess inter-observer agreement.ResultsInfoKeep scores were significantly different across the classifications (p ≤ 0.01) due to low scores for Wigglesworth and Aberdeen. CODAC received the highest mean (SD) score of 3.40 (0.73) followed by PSANZ-PDC, ReCoDe and Tulip [2.77 (1.00), 2.36 (1.21), 1.92 (1.24) respectively]. Wigglesworth and Aberdeen resulted in a high proportion of unexplained stillbirths and CODAC and Tulip the lowest. While Ease scores were different (p ≤ 0.01), all systems received satisfactory scores; CODAC received the highest score. Aberdeen and Wigglesworth showed poor agreement with kappas of 0.35 and 0.25 respectively. Tulip performed best with a kappa of 0.74. The remainder had good to fair agreement.ConclusionThe Extended Wigglesworth and Amended Aberdeen systems cannot be recommended for classification of stillbirths. Overall, CODAC performed best with PSANZ-PDC and ReCoDe performing well. Tulip was shown to have the best agreement and a low proportion of unexplained stillbirths. The virtues of these systems need to be considered in the development of an international solution to classification of stillbirths. Further studies are required on the performance of classification systems in the context of developing countries. Suboptimal agreement highlights the importance of instituting measures to ensure consistency for any classification system.

Stillbirths: Where? When? Why? How to make the data count?

“…The International Stillbirth Alliance has examined the usefulness of several classifi cation systems to identify the most prevalent causes in high-income settings. 56 The system introduced by Wigglesworth did worst, yet is the most widely used in low-income and middle-income countries because this system is simple to use and has been used for decades. 56 Even in Malaysia and South Africa, the application of new classifi cations were impeded by little placental or cord information, few other investigations such as karyotyping, placental histology, and thrombophilia screening, a total absence of post-mortem data, and reliance on maternal history.…”

“…56 The system introduced by Wigglesworth did worst, yet is the most widely used in low-income and middle-income countries because this system is simple to use and has been used for decades. 56 Even in Malaysia and South Africa, the application of new classifi cations were impeded by little placental or cord information, few other investigations such as karyotyping, placental histology, and thrombophilia screening, a total absence of post-mortem data, and reliance on maternal history. 56 Another problem, even in high-income countries, is detection of fetal growth restriction because of placental failure as a frequent antecedent of stillbirth.…”

“…14,57,58 By use of a complex classifi cation that includes fetal growth restriction and rigorous investigation, the unidentifi ed cause group can be reduced to less than 30% 56 or even less than 20%. 57,59 The poor comparability between multiple classifi cation systems is the most substantial barrier to any meta-analysis and estimates for stillbirth causation.…”

Audit into stillbirths: a tertiary hospital experience

“…[9][10][11] Other than identifying a cause for the fetal death, these systems have also pointed out the trends and preventing strategies of this stillbirths. 11 Lack of uniform definitions and incomplete registration are the main drawbacks to have an accurate stillbirth data.…”

Classification of stillbirths by relevant condition at death (ReCoDe): a cross sectional study at a rural tertiary care centre in Kerala, India

“…3 The ReCoDe system is among the four classification systems (CODAC, PSANZ-PDC, ReCoDe, and Tulip) which performed well on the Infokeep score. 6 Among these classification systems, ReCoDe is used exclusively for stillbirths while the others are used for classification of all perinatal deaths.…”