Effects of intrauterine growth retardation on development of the gastrointestinal tract in neonatal pigs

Biol Neonate. 2005;88(1):66-72. doi: 10.1159/000084645. Epub 2005 Mar 21.


Background: Intrauterine growth retardation (IUGR) is a common problem in human and other species and increases the risk of death of the fetus and newborn during the perinatal period.

Objectives: This study was conducted to examine the influences of intrauterine growth retardation (IUGR) on development of the gastrointestinal tract in newborn pigs.

Methods: Ten animals from five litters were divided into five piglets with IUGR and five with normal birth-weight (NW). The IUGR category comprised animals with a birth weight 2 SD below the mean birth weight of the total population, while the NW category included animals with a birth weight within one SD of the mean birth weight in the total population. Animals were anesthetized and sampled within 2-4 h after birth and without suckling. The morphological changes of intestine and stomach of IUGR piglets were compared with NW ones. The expressions of IGF-I and receptors for growth hormone and insulin in intestinal mucosa were semiquantified using reverse transcription PCR.

Results: The results of our study indicated that the weights of the stomach, small intestine and small intestinal mucosa were significantly lower in IUGR compared with NW piglets (p<0.01). In addition, the lengths of the small intestine and colon in IUGR pigs were also significantly less than those of NW (p<0.05). Furthermore, insulin-like growth factor-I (IGF-I) mRNA level in intestinal mucosa of IUGR piglets was increased significantly (p<0.05), and the expression mRNA levels of insulin receptor and growth hormone (GH) receptor in the mucosa in IUGR piglets showed a tendency to be lower (p=0.17 and p=0.11, respectively) than those of the NW animals.

Conclusion: We conclude from the data that IUGR affects intestinal growth and morphology and is in associated with altered gene expression of growth-related proteins. We speculate that the morphological change and associated altered endocrine homeostasis contribute to lower growth rates of pigs affected by IUGR.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn
  • Birth Weight
  • Fetal Growth Retardation / metabolism
  • Fetal Growth Retardation / pathology*
  • Gastrointestinal Tract / growth & development*
  • Gastrointestinal Tract / pathology
  • Gastrointestinal Tract / ultrastructure
  • Gene Expression
  • Insulin-Like Growth Factor I / genetics
  • Insulin-Like Growth Factor I / metabolism
  • Intestinal Mucosa / metabolism
  • Intestinal Mucosa / pathology
  • Intestinal Mucosa / ultrastructure
  • Microscopy, Electron, Scanning
  • Organ Size
  • RNA / chemistry
  • RNA / genetics
  • RNA, Ribosomal, 18S / chemistry
  • RNA, Ribosomal, 18S / genetics
  • Receptor, IGF Type 1 / genetics
  • Receptor, IGF Type 1 / metabolism
  • Receptor, Insulin / genetics
  • Receptor, Insulin / metabolism
  • Receptors, Somatotropin / genetics
  • Receptors, Somatotropin / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Swine / growth & development*


  • RNA, Ribosomal, 18S
  • Receptors, Somatotropin
  • RNA
  • Insulin-Like Growth Factor I
  • Receptor, IGF Type 1
  • Receptor, Insulin