Placental pathology in relation to stillbirth and neonatal outcome in an extremely preterm population: a prospective cohort study

Objective To study associations between placental histopathology and stillbirth as well as neonatal outcome in a population born extremely preterm. Design Prospective cohort study. Setting Stockholm, Sweden. Population 167 infants born <27 gestational weeks during 2004–2007. Methods One senior perinatal pathologist, blinded to outcome data, evaluated all placental slides. Main outcome measures Intrauterine fetal death, small‐for‐gestational age, major neonatal morbidity (intraventricular hemorrhage ≥grade 3, retinopathy of prematurity ≥grade 3, necrotizing enterocolitis, cystic periventricular leukomalacia or severe bronchopulmonary dysplasia) and neonatal mortality. Additional outcome variables were Apgar score at 5 min, sepsis, and treated patent ductus arteriosus. Results Accelerated villous maturation was associated with a decreased risk for Apgar score <7 at 5 min ( p  = 0.041). Fetal thrombosis and low placental weight were associated with an increased risk for both intrauterine fetal death ( p  < 0.001 and p  = 0.011, respectively) and small‐for‐gestational age ( p  < 0.001 and p  < 0.001, respectively). Conclusion Placental histology may have prognostic value as it appears to be associated with intrauterine fetal death, as well as with being small‐for‐gestational age and assignment of a low Apgar score at birth.