Over the past decades maternal nutritional intake has been proven to affect the prenatal and postnatal development of the fetus as well as its long-term health (see (Jimenez-Chillaron et al. 2012) and (Lillycrop & Burdge. 2015) for recent overviews). In this journal, we have recently shown that maternal Western style diet gives rise to long lasting programming of the liver in adult mouse offspring (Pruis et al. 2014), affecting mostly the males. Moreover, we demonstrated that several aspects of sex-specific programming are already present in two-week old offspring (Mischke et al. 2013), i.e., well before puberty. The question arising now is if this sexual dimorphism was already present during prenatal development, and which factors contributed to its manifestation. This article is protected by copyright. All rights reserved.