Hypoplasia of the Parafacial/Facial Complex: A Very Frequent Finding in Sudden Unexplained Fetal Death

AIMS - To define firstly in man the localization and the anatomical boundaries of the parafacial respiratory group in the brainstem. Thereafter, to determine whether this center, given its essential role in the respiratory rhythm- generating circuit, showed abnormalities in sudden unexplained perinatal and infant deaths, like other nuclei and/or struc- tures of the brainstem and cerebellum checking vital functions, that we have previously reported. METHODS - In 67 brains collected from 29 stillbirths, 9 newborns and 29 infants, died of both known and unknown cause, an in-depth histological examination of the autonomic nervous system was made, according to the protocol rou- tinely followed by the Institute of Pathology, University of Milan. In particular we analyzed the parafacial and facial nu- clei in serial sections of caudal pons. RESULTS - We firstly identified and defined the normal structure of the parafacial/facial complex in control cases. Be- sides we diagnosed the hypoplasia of these nuclei in 75% of sudden unexplained fetal deaths and never after birth. CONCLUSIONS - We formulate the hypothesis that the hypoplasia of the parafacial/facial complex is a specific marker of unexplained stillbirth, and that the normal development of this complex is essential for extra-uterine life.