Risk scoring systems for preterm birth and their validity: a systematic review

Abstract

Introduction: Nowadays, preterm birth (PTB) remains a heavy issue in children morbimortality. The risk stratification of PTB and its prediction are a challenge. Many risk factors associated with PTB have been identified and risk scoring systems (RSS) have been developed to face this challenge. The objectives of this systematic review were to identify RSS for PTB, the variables they consist of and their validity. Materials and methods: This review was developed following the PRISMA guidelines for systematic reviews. Two databases (PubMed and Web of Science) were searched from inception until the 12th of November 2022. Two authors independently performed the screening and eligibility phases. Records studying a RSS, based on specified variables, with an evaluation of the predictive value for PTB were considered eligible. Reference lists of eligible studies and review articles were also searched. Data from the included studies were extracted according to a data extraction form created for this purpose. Risk of bias was assessed based on the National Institutes of Health study quality assessment tool. Results: 56 studies, meeting the inclusion criteria, addressing a RSS for PTB, were included in this review. The most frequently incorporated variables in the RSS included in this review were maternal age, weight/body mass index, history of smoking, history of previous PTB and cervical length. The validity measures varied widely among the studies, with sensitivity ranging between 4,2% and 92,0% and AUC between 0,59 and 0,95. Conclusion: Despite the recent technological and scientifical evolution with better understanding of variables related to PTB and definition of new ultrasonographic parameters and biomarkers associated with PTB, the RSS ability to predict PTB remains poor in most situations, thus compromising the integration of a single RSS in clinical practice. The development of new RSS, the identification of new variables associated with PTB, and the elaboration of a large reference dataset might be a step forward to tackle the problem of PTB.