Urinary profiles associated with bacterial metabolites from asymptomatic pregnant women with at term or preterm premature rupture of membranes: a pilot study.

Objective: Premature rupture of membranes (PROM) and preterm premature rupture of membranes (pPROM) are frequent conditions with a not fully understood multifactorial etiology. It has been suggested that infection may be the leading cause of pPROM. Metabolomics is nowadays recognized as a successful and versatile approach for the investigation of several pathological conditions, including pregnancy-related ones. However, collecting samples such as fetal fluids or placenta poses a limit on the clinical application of this strategy. Therefore, the aim of this study was to detect urinary metabolites that could be associated with bacterial infection in PROM and pPROM and to understand its role in these different conditions, using readily available samples such as urines.Methods: Urine samples were collected from pregnant women who experienced rupture of membranes: (1) at term (≥37 weeks) not in labor (NLPROM); (2) at term in labor (LPROM); (3) preterm (<37 weeks) not in labor (pPROM). Samples were analyzed using a GC-MS platform. Student's t-test, Pearson correlation coefficient, principal component analysis (PCA), and partial least squares discriminant analysis (PLS-DA) were applied to observe differences between groups.Results: Results showed that lactic acid, erythritol, and ethanolamine levels were significantly higher in pPROM than in PROM (NLPROM + LPROM considered as one single group). These three metabolites might be associated with bacterial infections since they derive from bacterial metabolic processes and environments.Conclusions: This study might be useful to understand the mechanisms underlying the etiology of pPROM and PROM, and urine samples might represent a useful and readily available sample to discriminate preterm high-risk women.