Placental acute inflammation infiltrates and pregnancy outcomes: a retrospective cohort study

Abstract

Chorioamnionitis can be either an infection or a sterile inflammation. This study aims to analyze the prevalence of acute inflammatory lesions of the placenta, the association with a positive result of the microbiological examination, and the fetal-maternal outcomes. This retrospective study considered all single, consecutive pregnancies and their placental pathological examination during 2014-2017. The evidence of funisitis, chorionic vasculitis, and chorioamnionitis was assessed by a pathologist, including stage and grade. Moreover, maternal fever, placental microbiological examination, and neonatal outcomes were also recorded. Among the 5910 pregnancies in the considered period, 1770 had a placental pathological examination, and 358 (6.06%) had acute placental inflammation. Microbiological examination was performed in 125 cases, revealing 64 cases with a positive microbiological outcome. In the presence of acute placental inflammation, there was a higher rate of neonatal cardiopulmonary resuscitation, admission to neonatal intensive care unit, and postnatal death of the newborn. Multivariate analysis inferred that acute inflammation of membranes was a risk factor for neonatal cardiopulmonary resuscitation (OR 2.12; CI.95 1.36-3.31; p < 0.05), acute funisitis was a risk factor for admission to intensive neonatal care unit (OR 3.2; CI.95 1.67-6.12; p < 0.05), and chorionic vasculitis was a risk factor for postnatal death of the newborn (OR 5.38; CI.95 1.37-21.06; p < 0.05). The prevalence of chorioamnionitis was 6.06%, and about half of the cases were sterile inflammation. Chorioamnionitis was associated with higher rates of adverse fetal and neonatal outcomes; in particular, chorionic vasculitis was a risk factor for postnatal death.

Figure 1

(A–C) show gross and microscopic figures from placenta (acronyms: UC  umbilical cord, CP  chorionic plate, CV  chorionic villi, BP  basal plate [maternal side of the placenta]). (A) Illustrates the whole placenta with membranes and umbilical cord. (B) Gross figure that is taken from through placenta section. (C) Whole placenta thickness microscopic figure. (D) Prevalence of positive swabs in cases of acute inflammation of the placenta. (E) Isolated elements (all positive samples).