Gene expression patterns of insulin-like growth factor 1, insulin-like growth factor 2 and insulin-like growth factor binding protein 3 in human placenta from pregnancies with intrauterine growth restriction

Introduction: In this study, we compared insulin-like growth factor (IGF)-gene expression patterns and characteristics of glucose and insulin metabolism in human placenta from pregnancies with or without intrauterine growth restriction (IUGR). Materials and methods: We compared 101 human placentas from intrauterine growth restriction pregnancies to those of 140 normal pregnancies treated at our department in a one-year period. We have also assessed the serum glucose and insulin levels of the IUGR and control groups. Several possible predicting factors of IUGR were also investigated. Results: Risk for IUGR was suggested by gestational weight gain and gestational increase in maternal body mass index (BMI) as well as maternal birthweight. In pregnancies without IUGR, umbilical cord glucose and insulin levels were significantly higher than in pregnancies with IUGR. In placentas from pregnancies with IUGR an overexpression of the IGF-2 and the insulin-like growth factor binding protein (IGFBP)-3 genes was found. In placentas from pregnancies with male fetal gender we found a significant overexpression of the IGF-2 gene. Discussion: Gestational weight gain and BMI increase seem to predict the development of IUGR. Insulin and carbohydrate metabolism are also impaired in IUGR fetuses. In the placentas from pregnancies with IUGR, IGF-2 is overexpressed reflecting its physiological role in optimizing energy distribution in a low-energy environment.