Placental Heterogeneity in Stillbirth and Its Relations to Maternal Exogenous Characteristics

Introduction: Heterogeneous patterns of placental lesions in stillbirth signal important variations in placental histopathology that may be diagnostic in stillbirth. We explore placental heterogeneity and its associations with maternal characteristics (including HIV) using latent class analysis. Methods: Placental and maternal data and slides were assessed retrospectively for 122 confirmed stillbirths (gestational age >= 28 weeks) delivered at a major South African academic hospital between January 2016-July 2018. The slides were reviewed by 2 pathologists and classified using the Amsterdam Consensus Classification System. Latent class analyses were conducted on raw data. Results: We identify 5 latent placental classes in stillbirth based on similarity in patterns of observed diagnostic criteria and their associations with maternal characteristics. Three classes bear similarity to generalized patterns of placental injury identified previously. Our study shows that intrauterine infection was the commonest histopathological condition associated with stillbirth in our setting. Novel findings include 2 classes, distinguished by high placental RPH and maternal HIV, respectively, and the non-emergence of a class distinguished by VUE. Conclusion: The size and content of the latent classes and their similarity/dissimilarity to the more generalized patterns identified previously suggest potential new avenues for investigation and theory development concerning the role of the placenta in stillbirth and the impact of HIV.