Median concentrations (IQR) of profiled compounds relative to creatinine concentration at the three visits, and patient-wise fold-change between visits.

aWhile the median (IQR) values are reported on their natural scale, all parametric statistical tests were carried out using the log-transformed, normally distributed variables.bVisit V1: gestational week 8–20; V2: gestational week 26–30; V3∶10–16 weeks post partum.cUrea is affected by NMR water suppression.dBroader spectral signal; measured before subtracting BXR baseline.eCompound very dilute to undetectable in a substantial number of samples; reported concentration may represent noise.fConcentration of creatinine is reported as absolute mM before normalization.gNo conclusive identification, quantified as stated.xConcentrations of unidentified signals in arbitrary units, but nonetheless individually normalized to creatinine.