Summary. Because of its possible adverse effects on human health and its ubiquitous nature, Bisphenol A (BPA) is gradually replaced by presumably safer alternative such as Bisphenol S (BPS). However, data regarding the effects of developmental exposure to BPS on pregnancy and fetal outcomes is very scarce. The aim of this study was to evaluate the effects of developmental exposure to a very low dose of BPS on pregnancy and fetal outcomes and to study whether epigenetic modifications at the level of the placenta could mediate those effects. We showed that perinatal exposure to BPS, even at a very low dose can significantly affect pregnancy and fetal outcomes through disruption of placental transcriptome and epigenome. Exposure to a very low dose of BPS reduced mating success rate, while comparable dose of BPA did not affect this parameter. Exposure to this very low dose of BPS affected placental expression of Fut 2, Psg 22 and Wnt7b genes, involved in early placental development. Placental DNA methylation and mRNA expression of steroid receptor coactivator 2, a key mediator of steroid response, was significantly altered by exposure to the low dose of BPS. Exposure to this very low dose of BPS also led to lower weight of male and female offspring. This growth restriction persisted until adulthood in females but not males. These results suggest that early exposure to a very low dose of BPS impacts pregnancy outcomes though placental dysregulation.

This project is part of the PhD thesis of Julie Fudvoye and was held at the laboratory of Prof. Anne-Simone Parent (GIGA-Neuroscience, University of Liege, Belgium).

Related publication