Fig. 3

Fetal metabolite levels between sFGR and MCDA. A PLS-DA of the cord plasma metabolome between the sFGR and MCDA groups. Component 1: the set of coefficients that produces component scores that have the biggest difference between experimental factors. Component 2: the second set of coefficients that explains the second most variability between experimental factors. Circles in PLS-DA represent 95% confidence intervals (CI); each point in the figure represents a sample, and samples in the same group are represented by the same color. PLS-DA, partial least squares discriminant analysis. B Box plot showing the cord plasma metabolite levels between the sFGR and MCDA groups and their correlation with the maternal plasma metabolite levels in the third trimester. Mann–Whitney U tests were used for nonparametric comparisons between two groups. The metabolite levels in cord plasma and maternal plasma were determined as Log2-transformed metabolite concentrations (μM). Data were presented as the median and interquartile range (25–75%). The correlation between the metabolite levels in cord plasma and maternal plasma in the third trimester was examined using Spearman’s correlation, and Spearman’s correlation coefficients (R) were used to present the correlation between the two groups. The shadow around the linear regression trendline shows the 95% CI. sFGR, selective fetal growth restriction; MCDA, normal monochorionic diamniotic twins; CP, cord plasma; MP, maternal plasma; *P < 0.05, **P < 0.01