Restitution of swallowing in the fetal sheep restores intestinal growth after midgestation esophageal obstruction.

We have shown that, in the fetal sheep, abolition of fluid ingestion early in gestation results in a profound gastrointestinal tract (GIT)-specific growth retardation and that these effects can be reversed if fetal swallowing is restored, even for relatively short periods (15 days). The fetal esophagus was ligated at 60-65 days of gestation in 11 fetal sheep (term is 145-148 days). At 136 days of gestation, body and tissue growth of six fetuses were compared to eight age-matched control fetuses. There were no effects on body growth, but the growth of the GIT was significantly retarded. The small intestine was the most severely affected region; villi were smaller in both proximal and distal regions, and villus density was increased and crypt density decreased. The growth-retarding effects are progressive such that they become more pronounced as the period of absence of swallowed input to the GIT is increased. Thus the effects observed in our study (ingestion abolished for approximately 80 days) are much more marked than those in our earlier short-term studies (40-50 days). Five of the fetuses with esophageal ligations underwent further surgery at approximately 120 days' gestation to correct the esophageal obstruction so as to allow the resumption of fluid ingestion. By 136 days, the values of most intestinal morphological parameters had begun to move toward control values.(ABSTRACT TRUNCATED AT 250 WORDS)