Poster session I Clinical obstetrics, epidemiology, fetus, medical-surgical complications, neonatalogy, physiology/endocrinology, prematurity: Abstracts 87 - 236| Volume 208, ISSUE 1, SUPPLEMENT , S104-S105, January 01, 2013

228: Micro PET imaging in pregnancy: acute and chronic maternal nutrient availability alters in vivo fetal and tissue glucose uptake


      Micro Positron Emission Tomography (mPET) is a non-invasive,functional imaging tool used to quantify in vivo tissue glucose uptake (GU). Our goal was to measure the effect of chronic maternal diets and acute lipid load on fetal-placental GU and maternal cardiac GU in pregnant dams using mPET.

      Study Design

      Four groups of age-matched, female SD rats were studied:1)CON(n=6)standard chow ad libitum, 2) CR(n=9)Calorie Restriction,pair-fed 60%CON kcal/d of standard chow from D11 of gestation, 3) WD(n=7)Western Diet from 3 weeks through gestation, and 4) ALL(n=7) Acute Lipid Load,normal dams fed an oral lipid load 4 hours prior to study. On D19 of gestation, dams were given IV radiolabeled 18F-fluorodeoxyglucose to measure tissue GU and mPET was performed. ASIPRO (Siemens) software was used to localize regions of interest (ROI), defined as 5 image slices representing maximum concentration of fetus/placenta. For each animal's ROI, the mean GU was calculated in SUVs (standard uptake value). A 3-point scale quantified maternal cardiac GU (0=none, 1=minimal, 2=maximal).


      CON weighed more than CR (302±8g vs 268±14g,p<0.01) and WD more than Con and ALL(384±9.6g vs 302±8g, 297±18g p<0.01). Pup weight and litter size were similar between groups. CR and WD dams demonstrated increased fetal-placental GU and decreased maternal cardiac GU compared to CON [Figure]. Similarly, in response to acute lipid load, ALL dams had increased fetal-placental GU with a decrease in maternal cardiac GU [Table].
      Tabled 1Maternal cardiac glucose uptake and traced region of interest (ROI)
      Table thumbnail grr93


      Similar to acute lipid load, chronic maternal CR and WD results in increased fetal-placental GU and decreased maternal cardiac GU. These findings suggest that both calorie restriction and chronic high fat feeding in pregnancy induces greater maternal reliance on lipid oxidation, therefore making more glucose available for transport to the fetus. In pregnant models, mPET may be a valuable tool not only to measure in vivo glucose transport, but also transport of other nutrients, such as lipids.