Chorioamnionitis and congenital abnormalities of the brainstem (arcuate nucleus and pre-Bötzinger complex hypoplasia) in a case of late unexplained stillbirth

Background: Fetal death (stillbirth), that occurs every 100-200 pregnancies in industrialized countries, has not significantly decreased in recent years, mostly because of scarce research activities in this field. Fetal death is often, in up to 60-80% of cases, unexplainable, even after routine diagnostic examinations. Objectives: This work aims to stress the importance of in-depth histopathological investigations of both the autonomic nervous system and the placenta, in sudden fetal death. Methods: In a case of late fetal death at 40+3 weeks of pregnancy an in-depth histopathological examination of the brainstem and of the placenta was performed. Results: The case investigated in this work showed severe hypoplasia of the arcuate nucleus as well as of the reticular formation and particularly of the pre-Bötzinger complex. Pulmonary hypoplasia was also present, associated with a picture of severe (grade 3) chorioamnionitis, with inflammatory, mostly granulocytic, infiltrate, vasculitis of the umbilical vein and amniochorionic vessels. Conclusions: The chorioamnionitis can allegedly contribute to stillbirth, through cytokine release, enhancing any chemoreceptor neuronal dysfunction.