Our objective was to identify metabolites associated with fetal growth restriction (FGR) by examining early and late pregnancy differences in non-targeted urinary metabolites among FGR cases and non-FGR controls. An exploratory case-control study within LIFECODES birth cohort was performed. FGR cases (N = 30), defined as birthweight below the 10^th percentile, were matched with controls (N = 30) based on maternal age, race, pre-pregnancy body mass index, and gestational age at delivery. Gas chromatography/electron-ionization mass spectrometry was performed on urine samples collected at 10 and 26 weeks of gestation. Differences in urinary metabolite levels in cases and controls at each time point and between the two time points were calculated and then changes compared across pregnancy. 137 unique urinary metabolites were annotated, and several identified that were higher in cases compared to controls. For example, urinary concentrations of benzoic acid were higher in cases compared to controls at both study visits (3.01-fold higher in cases at visit 1, p < 0.01; 3.10-fold higher in cases at visit 3, p = 0.05). However, these findings from our exploratory analysis were not robust to false-discovery-rate adjustment. In conclusion, using a high-resolution, non-targeted approach, we found specific urinary organic acids differed over pregnancy by FGR case status.

我们的目标是通过检查FGR病例和非FGR对照之间的非靶向尿代谢物的妊娠早期和晚期妊娠差异来鉴定与胎儿生长受限（FGR）相关的代谢物。在LIFECODES出生队列中进行了一项探索性病例对照研究。FGR例（N = 30），定义为10的下方出生体重^日根据孕产妇年龄，种族，孕前体重指数和分娩时的胎龄，将百分位数与对照组（N = 30）匹配。气相色谱/电子电离质谱法是在妊娠10和26周时收集的尿液样品上进行的。计算出每个时间点以及两个时间点之间病例和对照中尿液代谢物水平的差异，然后比较整个怀孕期间的变化。注释了137种独特的尿液代谢产物，发现其中几种与对照组相比较高。例如，在两次研究访问中，病例中尿酸的苯甲酸浓度均高于对照组（访问1中的尿酸浓度高3.01倍，p <0.01；访问3中的尿酸浓度高3.10倍，p = 0.05）。然而，我们的探索性分析得出的这些结果对于错误发现率的调整并不可靠。总之，使用高分辨率，非针对性的方法，我们发现特定的尿有机酸在整个怀孕期间因FGR病例状况而有所不同。