Fig. 1From: Relationship between amniotic fluid metabolic profile with fetal gender, maternal age, and gestational weekMultivariate analysis of the influence of the fetal gender on the AF metabolic profile. A Two dimensional unsupervised PCA analysis; B Supervised OPLS-DA, R2Y = 0.340; Q2 = -0.224. A negative Q2 value indicated an over-fitting of the modelBack to article page