Placental lesions in stillbirth following the Amsterdam consensus: A systematic review and meta-analysis

Placental disorders remain one of the main causes of stillbirth. However, the lack of standardised nomenclature has significantly limited the clinical utility of placental histology. Following the Amsterdam consensus classification, which now allows proper comparisons of placenta histology across the world, we conducted the first systematic review and meta-analysis (Prospero CRD42023410469) to assess the commonest stillbirth-associated placental lesions worldwide. Eighteen studies with 3082 placentas were included. Maternal vascular malperfusion and fetal vascular malperfusion were the most prevalent placental lesions in stillbirth, and significantly more frequent in stillbirths than livebirths [OR 3.0 (95 % CI 2.0-4.5), p < 0.001 and OR 5.12 (95 % CI 3.09-8.47), p < 0.001, respectively]. However, when adjusting for gestational age, only maternal vascular malperfusion remained significant at term. Better understanding of the pathophysiology underlying placental lesions is needed to inform timely risk assessment and therapeutic interventions capable of reducing placental-related stillbirths.