Proteome analysis of daily urine samples of pregnant rats unveils developmental processes of fetus as well as physiological changes of mother rats

Significant physiological changes occur in both fetus and mother during pregnancy. Urine proteins have been shown to reflect a wide range of physiological and pathological changes in the body. To comprehensively explore the daily changes in urine proteins during pregnancy, this study employed low-abundance protein-enriched magnetic nanobeads to conduct an in-depth analysis of the daily changes in urine proteins throughout the entire pregnancy of rats. Based on the 3,455 identified urine proteins, fetal and maternal dynamic changes were observed in the pregnancy group compared to the control group, including blastocyst formation and cell division in the early stage of pregnancy, embryonic development and organ morphogenesis in the intermediate and mid-to-late stages of pregnancy, and maternal-specific change such as lactation in the late stage of pregnancy. These results indicate that urine protein can reflect the fetal and maternal dynamic physiological alterations during pregnancy, which suggests the potential value of urine protein analysis in pregnancy health monitoring. It is emphasized that the analysis focuses on the daily variations in the urine proteins, as these daily changes are expected to reveal more dynamic and detailed information about the physiological processes during pregnancy.