RESTRICTION OF NUTRITION IN-UTERO SELECTIVELY INHIBITS GASTROINTESTINAL GROWTH IN FETAL SHEEP

This study examined the effects of reduced nutrition on fetal growth o ver the first half of gestation. Reduced nutrition was achieved by a c ombination of reduced maternal food intake and carunclectomy, a proced ure which restricts the development of the placenta. There were no maj or effects of restriction on fetal body, tissue or organ growth, excep t for the gastrointestinal tract (GIT). Total GIT weight was lower in restricted fetuses than in controls. More specifically, it was growth of the small and large intestine which was compromised. Small intestin al weight was significantly lower, both in absolute terms and relative to body weight. The intestinal diameter and mucosal area were signifi cantly lower in both small and large intestine of restricted fetuses. Maturation of enterocytes was also delayed in nutrient-restricted fetu ses. In addition, there were focal lesions of the brush border present , indicating abnormal epithelial differentiation. By term, in growth-r etarded fetuses, growth deficits in many organs were present, includin g the GIT. The present study suggests that GIT growth deficits may hav e a long-term etiology, including at their onset, abnormal cellular di fferentiation. These results could explain why GIT function in intraut erine growth-retarded infants is more likely to be compromised than in premature or term infants.