INFLAMMATION OF THE LUNGS, UMBILICAL-CORD AND PLACENTA ASSOCIATED WITH MECONIUM PASSAGE IN-UTERO - REVIEW OF 123 AUTOPSIED CASES

It is uncertain how often the passage of meconium in utero is a respon se to some event causing fetal distress as opposed to being simply the physiologic functioning of a maturing intestinal tract. The extent to which meconium may produce injury or inflammation in pulmonary and pl acental tissues after intrauterine exposure is also unclear. This stud y was a retrospective review of 123 cases, 79 stillborn and 44 livebor n less than one month of age, autopsied at The Johns Hopkins Hospital, and showing histologic evidence of intrauterine meconium exposure by aspirated meconium or meconium macrophages in placental tissues. Of 55 cases with pulmonary inflammation, 13 (24%) had fetal pneumonia, 5 (9 %) had postnatal bronchopneumonia, and 37 (67%) had inflammation secon dary to meconium aspiration. There was inflammation of the umbilical c ord in 31 (41%) of the 75 cases with available slides, 11 (15%) had fu nisitis associated with chorioamnionitis and 18 (58%) were secondary t o meconium exposure. There were 19 cases with focal injury of cord ves sels from meconium, two of which had cord ulceration. Inflammation of the membranes and chorionic plate was present in 24 (33%) of the 72 ca ses where it could be assessed, and was due to chorioamnionitis in 11 (46%) and to meconium in 13 (54%). In general, meconium-related inflam mation was much less severe in the membranes than in the cord. There w ere 67 (54%) cases with definite or probable evidence of fetal distres s. In 38 (48%) stillborns no cause of fetal death in utero was identif ied and in 18 (41%) liveborns there was no known prenatal problem. The results support the concept that meconium passage in utero may occur either as a response to fetal distress or as a physiologic process. In flammation in the lung and placental tissues, and vascular injury in t he umbilical cord may arise secondary to in utero exposure to meconium .