Fig. 3From: Relationship between amniotic fluid metabolic profile with fetal gender, maternal age, and gestational weekMultivariate analysis of the influence of the gestational week on the AF metabolic profile. A Two dimensional unsupervised PCA analysis; B In the PLS-DA model, the Q2 value of the first three component was -0.14. A negative Q2 value indicated an over-fitting of the modelBack to article page