Creating a placental inflammatory composite index that has a high prognostic relevance to child morbidity

Aim Selecting pathologic measures of placental inflammation that affect pregnancy and childhood health is largely empirical. We aimed to systematically select several core inflammation-related placental measures to construct a novel placental inflammatory evaluation criterion with a high prognostic relevance to child morbidity. Methods We used data from the US Collaborative Perinatal Project (1959–1976), a longitudinal birth cohort study that recruited women during pregnancy and followed the children until 7 years of age. Bootstrap resampling, least absolute shrinkage and selection operator, and receiver–operator curve were used to select placental pathologic measures that were closely related to child morbidity to form a placental inflammatory composite index. Results Twenty-six candidate placental inflammation-related measures were ranked based on their close association with adverse neonatal outcomes. The top five placental measures were: (i) neutrophilic infiltration in umbilical artery; (ii) placental weight–birthweight ratio; (iii) necrosis in decidua capsularis; (iv) bacterial colony in epithelium of amnion; and (v) opacity of membranes and fetal surface. Several composite indexes were constructed. A five-measure composite index that had the highest prognostic relevance was chosen. Compared with subjects without any of the five abnormal measures, those with any lesion ranging from 1 to 5 had a 1.2- to 4.6-fold risk of adverse child outcomes, respectively. Conclusion Our composite index is simple, evidence-based, and has predictive value for child morbidity. It may be used as a novel placental inflammatory evaluation criterion.