Association between cerebral palsy and microscopically verified placental infarction in extremely preterm infants.

Abstract

Previously, cerebral palsy has been associated with placental infarctions diagnosed macroscopically by midwifes. However, the risk of misclassification of infarctionsis is high without a histological verification. Therefore, the objective of this study was to study placental histopathology in relation to developmental outcome at 2.5 years corrected age in a population born extremely preterm. A prospective cohort study was carried out at Karolinska University Hospital, Stockholm, Sweden on a population of 139 live born infants delivered <27 gestational weeks during 2004-2007. A senior perinatal pathologist, who was blinded to outcome data, evaluated all placental slides microscopically. Neuromotor and sensory functions of the children were evaluated. Bayley Scales of Infant and Toddler Development-III (Bayley-III) were used to assess development at corrected age 2.5 years. The outcome data were evaluated without reference to obstetrical and pathology data. The primary outcome measure was neurological and developmental status at 2.5 years of corrected age. This was measured as diagnosis of cerebral palsy, visual impairment, hearing impairment as well as performance on Bayley-III scales evaluating cognitive, language and motor functions. Two out of seven children with placental infarction were diagnosed with cerebral palsy compared with one child of 51 without placental infarction (p = 0.036). For developmental outcome according to Bayley-III at 2.5 years no statistically significant associations with placental pathology were found. A possible association between placental infarction, verified by microscopic examination, and cerebral palsy has been identified in this extremely preterm population.