ESOPHAGEAL LIGATION - EFFECTS ON THE DEVELOPMENT OF FETAL ORGANIC-SYSTEMS

The role of amniotic fluid ingestion on the development of various fet al organic systems was evaluated in the rabbit model. The fetuses from 24 New Zealand white rabbits were studied on the 23rd day of gestatio n. Right ovarian-end fetuses underwent esophageal ligation (EL) or sha m (SH) operations. Rabbits were submitted to hysterectomy on gestation al day 30, and various organic systems of live fetuses were examined b y weight and histological evaluations. Additionally, small intestinal enzymes were determined. Three fetal deaths, one in EL and two in SH g roups, occurred with a total survival rate of 85%. EL resulted in incr eased amniotic fluid volume. Although fetal body weights (BW), lung, h eart, liver and renal weights and liver weight/BW, lung weight/BW rati os did not differ, gastric, small intestinal and total gastrointestina l tract weights significantly decreased in EL group (p<0.05). Addition ally, gastric weight/BW, small intestinal weight/BW, total gastrointes tinal tract weight/BW and renal weight/BW ratios were also significant ly decreased (p<0.01). Sucrase and maltase activities were not detecta ble in either group. Lactase activity in proximal small intestinal tis sue was significantly decreased in EL group (p<0.05). Mid and distal s mall intestinal tissue lactase activities did not reveal any significa nt difference among groups. Histologically, alveolar enlargement and a lveolar thickening in fetal lungs, decreased glomerular count and tubu lar degeneration in fetal kidneys, and slight changes in fetal livers such as cellular vacuolization and reduction in central vein count wer e observed in the fetuses with esophageal ligation. While small intest inal tissues showed no marked changes, fetal stomach tissues in EL gro up revealed marked histological alterations consistent with erosive ga stritis. This study suggests that amniotic fluid ingestion has no impo rtant effects on fetal somatic growth but effects the development of v arious fetal organic systems. Since the nutritional role of amniotic f luid is obscure, changes in amniotic fluid dynamics, and/or impairment of release of some possible fetal organotrophic factors, and/or unuse d states of the organs may be responsible for the morphologic changes secondary to esophageal ligation.