HypothesisAn influx of amniotic fluid cellular content (AFCC) into the middle ears during birth may lead to the development of a chronic inflammatory process in the form of varying amounts of granulation tissue even if signs of otitis media are absent. This foreign body neonatal otitis media may predispose the child to recurrent otitis media.BackgroundForeign body neonatal otitis media caused by AFCC was described by Aschoff and elaborated by Wittmaack 100 years ago. Recent studies have shown how AFCC spreads to various middle ear compartments and causes histologic changes, the severity of which is related to the amount of AFCC. Specific elements become phagocytized after the first months of life but have caused the formation of inflammatory polyps and granulation tissue with round cell secretions in the meantime.MethodsTen temporal bones from the Temporal Bone Foundation, derived from infants aged 5 months to 1 year 11 months, were serially sectioned at 20 &mgr;m, saved at 0.2-mm intervals, numbered, and stained with hematoxylin and eosin. Every slide was studied for the presence, nature, and stage of pathologic tissue changes of the middle ear and the mastoid antrum.ResultsPseudocystic granulation tissue was massive in the temporal bone of the 8-month-old child born through thick meconium. Severe changes were present in the temporal bones of two infants aged 5 months, one of which showed traces of AFCC. In the temporal bones of two older children, long-standing changes were minor, one of them still showed traces of AFCC. Fresh acute changes and long-standing histologic changes occurred side by side.ConclusionsNeonatal otitis media caused by AFCC can give rise to extensive granulation tissue and round cell secretion, which is likely to make the ear susceptible to infectious otitis media. Cumulative development of granulation tissue as a result of infection may lead to blockage of attic aeration and drainage pathways, causing irreversible adhesive otitis media. A data base should be formed of all neonates born through meconium-stained amniotic fluid to allow a comparison with those born through clear fluids. Surgery with the creation of auxiliary aeration pathways becomes advisable in the treatment of ears with massive development of granulation tissue.