THE PATHOGENESIS OF INTRAUTERINE PNEUMONIA

Abstract

PNEUMONIC changes can be found in the lungs of a substantial proportion of the fetuses which die in utero in the late stages of gestation. Similar alterations found in the lungs of percentage of liveborn infants who for only a few hours or day. In the first instance it is certain, in the second it is generally assumed that the process had its origin within the uterus. In an additional number of both stillborn and liveborn infants, it may be demonstrated by microscopic examination that there is an excessive quantity of amniotic sac contents within the lungs. The pathogenetic factors responsible for both intrauterine pneumonia and for excessive aspiration of amniotic contents have never been definitely established. There still exit profound differences of opinion on every aspect of the process of intrauterine respiration. The following represent expert opinions on the question as to whether the fetus "breathes" or not. Snyder and Rosenfeld state that "in the full-term fetus sponataneous rhythmic respiratory movements occur which may continue many hours. "Davis and Potter maintain that "amniotic fluid is normally aspirated into lungs as part of intrauterine respiratoy activity" and concluded that "an adquatic existence for the fetus is normal during intrauterine life." Windle has arrived at the opposite conclusion. In 1939 he wrote,"One is tempted to entertain the false assumption that respiration at birth is a continuation of respiratory-like phenomena indulged in normally throughout fetal life. This is contrary to fact." Sir Joseph Barcroft came to the same conclusion. "There is during the second half of fetal life an inhibition of the nervous mechanism responsible for respiratory movements. If there were not the fetus would be drowned before it was born."