DIABETES IN PREGNANCY - UTERINE BLOOD FLOW AND EMBRYONIC-DEVELOPMENT IN THE RAT

The uterine blood flow to individual implantation sites was evaluated in early normal and diabetic rat pregnancy, and related to maternal me tabolic state: length of gestation, and embryonic outcome. The aim was to search for a possible coupling between the flow rate and embryonic development. We studied pregnant rats of a malformation-prone Sprague -Dawley strain on gestational d 9, 10, 11, and 12, a time period which roughly corresponds to postconception wk 3-6 in human gestation, The blood flow in the uterus was estimated with the aid of a microsphere t echnique, and the embryos were evaluated with respect to morphology an d uterine position, We found increased blood flow in the uterine and d ecidual tissue of the pregnant diabetic animals compared with normal p regnant rats on all days studied. The blood perfusion peaked on gestat ional d 10, both in normal and diabetic pregnancy. The implantations t ended to be fewer, whereas the resorption and malformation rates were higher, in the left hem than in the right horn, The blood flow in the uterine and decidual tissues was increased in the left hem in diabetic d 10 tissue, as well as d 12 tissues, thereby suggesting that comprom ised embryonic development is associated with increased rather than de creased supply of nutrients to the implantation site, These findings a re in concert with previous in vitro results suggesting that enhanced oxidative stress due to increased substrate availability is an importa nt factor in diabetic teratogenesis.