Peculiarities of glucose intake in fetal tissues in chronic hypoxemia
Objective — to investigate fetal blood distribution and glucose metabolism of heart, liver and brain during chronic hypoxaemia. Establishment of a model of real time measurement of the metabolic changes during chronic fetal hypoxaemia using PET-CT measurement in pregnant sheep after iatrogenic induction of chronic fetal hypoxaemia. Laser coagulation of placental vessels was performed in pregnant sheep in order to cause fetal hypoxaemia 14 days before the PET-procedure. The following PET-Scans were performed after 18F-FDG was injected into the jugular vein of the sheep. Fetal glucose uptake was scanned in fetal brain, liver, heart and kidneys during a period of 60 min after injection of the FDG tracer. Glucose uptake of these organs was measured in comparison with placental glucose uptake during the above-called 60 minutes course. Here we present the analysis of the metabolic changes in fetal hypoxaemia in a small series of 8 fetal sheep. It was found that FDG Uptake in the placenta, brain, liver and heart of the fetus was measured at normal oxygenation and in chronic hypoxia in 8 sheep fetuses, between 112 and 135 days of pregnancy (gestational age) 125±4 days (mean±SD). Umbilical cord artery resistance was significantly higher in hypoxemic fetuses compared to normoxemic. Venous duct reactions as a respond to hypoxia was observed. Index of pulsation in the umbilical artery was not significantly increased during hypoxia (1,06±0,18 та 1,67±0,12, р=0,018). PI in venous duct during chronic hypoxia (0,62±0,25) was increased in compare with normoxemic (0,41±0,2), but not significantly. Relative FDG uptake was about 3.8 times higher in brain of hypoxemic fetuses (0.019±0.005) compared to normoxemic (0.005±0.002), (р=0,02). In contrast, hypoxic fetal heart showed no significant difference in absorption of FDG compared to normoxemic fetal brain (p=0.11). Relative FDG uptake in the liver did not differ substantially between the two groups (p=0.97). Thus, it was shown that chronic maternal hypoxemia led to decreased placental and increased brain blood flow, although, glucose metabolism was not decreased in the fetal liver and heart.
2. Jensen A, Hohmann M, and Kunzel W. (1987). Redistribution of fetal circulation during repeated asphyxia in sheep: effects on skin blood flow, transcutaneous PO2, and plasma catecholamines. J. Dev. Physiol., 9, 41–55.
3. Kiserud, T., Rasmussen, S. & Skulstad, S. (2000). Blood flow and the degree of shunting through the ductus venosus in the human fetus. Am. J. Obstet. Gynecol., 182 (1), 147–53. DOI: 10.1016/S0002-9378(00)70504-7.
4. Salihu, H. M., Sharma, P. P., Aliyu, M. H., Kristensen, S., Grimes-Dennis, J., Kirby, R. S. & Smulian, J. (2006). Is small for gestational age a marker of future fetal survival in utero? Obstet. Gynecol., 107, 851–6. DOI: 10.1097/01.AOG.0000206185.55324.5b.
5. Surkan, P. J., Stephansson, O., Dickman, P. W. & Cnattingius, S. (2004). Previous preterm and small-for-gestational-age births and the subsequent risk of stillbirth. N. Engl. J. Med., 350 (8), 777–85. DOI: 10.1056/NEJMoa031587.
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