Fig. 2

Maternal metabolite levels in different trimesters between sFGR and MCDA. A PLS-DA of the maternal plasma metabolome in the different trimesters. B PLS-DA of the maternal plasma metabolome between the sFGR and MCDA groups in the first, second, and third trimester. 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. C Line plot showing the maternal plasma differential metabolite levels in different trimesters between sFGR and MCDA. Student’s t-test and Mann–Whitney U test were used for parametric or nonparametric comparisons in two groups. PLS-DA, partial least squares discriminant analysis; MP, maternal plasma; FT, first trimester, ST, second trimester, TT, third trimester; sFGR, selective fetal growth restriction; MCDA, normal monochorionic diamniotic twins; TMVAV, N, N, N-trimethyl-5-aminovaleric acid; Log2-transformed metabolite concentrations (μM) are presented as the mean ± standard deviation (SD). *P < 0.05, **P < 0.01, ***P < 0.001