Blood flows and nutrient uptakes in growth-restricted pregnancies induced by overnourishing adolescent sheep

Jacqueline Wallace, D A Bourke, Raymond Aitken, N Leitch, William Hay

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93 Citations (Scopus)

Abstract

To establish physiological mechanisms for fetal growth restriction in pregnant adolescent ewes we studied uterine, fetal, and uteroplacental metabolism in ewes offered a high (n = 12) or moderate (n = 10) dietary intake. High intakes decreased placental (226 vs. 414 g, P < 0.001) and fetal weight (3,323 vs. 4,626 g, P < 0.01). Uterine blood flow was reduced absolutely (-36%) but proportional to conceptus weight; umbilical blood flow was reduced absolutely (-37%) and per fetal weight (-15%). Uterine oxygen uptake was decreased per conceptus weight (-14%); there was no change in fetal weight oxygen consumption. Uteroplacental oxygen consumption and clearance were reduced proportional to weight. Similar changes were measured for glucose fluxes and fetal glucose concentration; fetal insulin concentration was reduced. In this model of fetal growth restriction, therefore, maintenance of fetal weight-specific glucose and oxygen consumption rates are producing relative hypoglycemia and hypoxemia. This indicates that increased fetal glucose clearance and/or insulin sensitivity may be operating as compensatory mechanisms to preserve normal fetal metabolism while fetal growth is sacrificed.

Original languageEnglish
Pages (from-to)R1027-R1036
Number of pages10
JournalAmerican Journal of Physiology-Regulatory Integrative and Comparative Physiology
Volume282
Issue number4
DOIs
Publication statusPublished - Apr 2002

Keywords

  • uterine blood flow
  • umbilical blood flow
  • placenta
  • fetus
  • intrauterine growth restriction
  • placental growth
  • fetal growth
  • glucose transfer
  • endocrine status
  • heat-stress
  • retardation
  • metabolism
  • ewes
  • consumption

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