“…Presence of placental lesions was abstracted from the clinical pathology reports of women with PTB and categorised according to proposed schemas as placental malperfusion (vasculopathy, infarct, accelerated villous maturation, perivillous fibrin deposition, intervillous fibrin deposition), intra-uterine infection/inflammation (III, acute chorioamnionitis, acute funisitis, acute vasculitis, acute deciduitis), villitis of unknown aetiology (a marker of chronic inflammation), fetal thrombosis or chorangiosis. 13,17,18 A detailed description of placental lesion definitions is provided in Supporting Information Table S1. [19][20][21][22] During this period, placental pathologists prepared all reports following a standardised protocol using a uniform reporting approach and identical diagnostic criteria.…”