Causes of death in the extremely low birth weight infant

Objective. To present primary and secondary causes of death confirmed by au topsy for the extremely low birth weight infant. Methods. A total of 111 infants weighing between 300 and 1000 g at birth wh o died and were autopsied at our hospital during the 4-year period 1990-199 3 were retrospectively reviewed. Clinical, pathologic, and laboratory data were retrieved including results of placental examinations and autopsy cult ures. Primary and secondary causes of death were assigned by the authors. Results. Infection was the most common primary cause (56/111) followed by r espiratory distress syndrome/bronchopulmonary dysplasia (24/111) and congen ital defect (15/111). Immaturity as an only cause appeared almost exclusive ly in infants weighing <500 g at birth. Infection was significantly underdi agnosed clinically with most of these deaths attributed to immaturity or re spiratory distress syndrome. In only 1 case was intraventricular hemorrhage considered the primary cause of death although it was present as a seconda ry cause in 19/111. Infections were divided into congenital (30/56) and acq uired (26/56) by time of death. The congenital infections (less than or equ al to 48 hours) consisted of pneumonia and chorioamnionitis/funisitis attri butable to maternal enteric organisms. Causative bacteria were obtained in pure culture in a number of these cases. The acquired infections were mainl y caused by yeasts and nosocomial bacteria. Sixty-seven percent of the deat hs occurred in the first 2 days and 12% were beyond the neonatal period at 29 to 104 days. Care was not initiated or was withdrawn in 50% of the infan ts, usually within the first 4 hours. Conclusions. Infection of the amniotic fluid leading to pneumonia was the m ajor cause of: death in the extremely low birth weight infant. Accurate cau se of death can not be reliably ascertained without an autopsy accompanied by examination of the placenta in the early deaths. Antibiotic treatment of the mother and infant may have reduced the deaths from infection. Early fa ilure to respond to neonatal intensive care may well indicate presence of a congenital pneumonia.