Impact of obesity and preconceptional bariatric surgery on feto-placental unit in a rat model: a preliminary study

Obesity and overweight in pregnant women increase pregnancy and neonatal morbidity with a risk of metabolic syndrome for children in later life. Maternal preconceptional bariatric surgery reduces maternal and paediatric outcomes but may induce fetal nutritional deficiencies and intrauterine growth restriction through placental reprogramming. The aim of this study was to describe feto-placental unit modifications induced by obesity, and the effect of bariatric surgery performed before gestation, on a diet-induced obese rat model. One month after surgery, rats of 'control', 'obese' and 'bariatric surgery' groups were mated and then sacrificed at D19 of gestation. Clinical description, immuno-histochemistry and molecular analyses were performed on feto-placental units. Obesity induces placental modifications including lipid accumulations, increased inflammation and oxidative stress. Some of these modifications are partially restored by maternal preconceptional bariatric surgery. On the other hand, a reduction in the expression of markers of glucose transport, insulin function and amino acid transport, after bariatric surgery was observed. This phenotype may lead to fetal caloric restriction, adoption of a 'thrifty phenotype' and subsequently fetal growth restriction. These preliminary findings highlight the importance of a close follow-up of women who have undergone bariatric surgery and their children.