The care of premature infants in the 20th century is remarkable for technical advances that have dramatically improved survival, but little is known about temporal changes in the neuropathology of the premature infant over this time frame. We hypothesize that the autopsy rate of germinal matrix hemorrhage changed in the 20th century relative to combined influences of clinical interventions that were both harmful and helpful. We examined germinal matrix hemorrhage with intraventricular hemorrhage (GMH-IVH) in 345 premature infants (gestational age 25-36 weeks) autopsied at Boston Children's Hospital from 1914 to 2015. There was a median of 19 cases/decade (range 7-68). Over the course of the study median gestational age decreased from 33 to 27 gestational weeks (P<0.001), and median postnatal survival increased from 2 to 26 days (P=0.02). The incidence of GMH-IVH increased from 4.7% before 1960 to 50.0% from 1975 to 1980, and then decreased to 12.5% after 2005 (P<0.001). The incidence of GMH-IVH increased >3-fold around the time of the introduction of positive pressure ventilation into premature intensive care in the mid-1960s. The increased incidence of GMH-IVH in the 1970s-1980s likely reflects respiratory and hemodynamic imbalances complicating mechanical ventilation. We speculate that the subsequent decreased incidence of GMH-IVH likely reflects stabilization of respiratory function with improvements in ventilators and in ventilator management beginning in the 1970s and the use of surfactant and antenatal steroids in the 1980s.
Keywords: history of neonatology; mechanical ventilation; neonatal intensive care unit; secular trends; surfactant.