Currently in pig production, approximately 21 % of total born piglets die before weaning, mainly during the first three days of life. Thus, piglet survival depends on the degree of development (i.e. piglet maturity) on the day of birth. In particular, foetal growth is closely related to the physiology and nutrition of the dam during gestation, as nutrients are transmitted from the endometrium to the foetus via the placenta. To study differences in foetal metabolism as a function of the degree of maturity, we studied two extreme pig breeds: Large White (a very productive line with high perinatal mortality) and Meishan (a less productive but more robust line). Sows from each line were inseminated with mixed semen from both lines, which generated pure and crossbred foetuses within the same sow. In this project, we compared biological mechanisms of the placenta of 224 late-gestation foetuses (at 90 and 110 days of gestation) using proton nuclear magnetic resonance (NMR) analyses. From multivariate analyses, we identified 20 discriminative metabolites between the two stages of gestation and 19 and 21 discriminative metabolites between foetal genotypes at 90 and 110 days, respectively. These metabolite intensities in placenta samples were correlated to phenotypes involved in the maturity status of piglets. In particular, placental myo-inositol concentration was negatively correlated with body mass index and positively correlated with the ratio of brain weight to body weight, illustrating growth retardation.