Objective: To evaluate the clinical application of protein-to-creatinine ratio (P/Cr) in spot urine samples so as to check whether it can replace urine protein excretion in 24 h collections for the diagnosis and screening of preeclampsia.
Methods: The investigators selected 100 cases of pregnant women with preeclampsia and 36 cases of normal pregnant women examined at Sir Run Run Shaw Hospital over the last two years. The correlations between P/Cr in first morning urine samples and urinary protein excretion in 24 h collections were analyzed. The cutoff values of P/Cr in first morning urine samples for screening preeclampsia of 0.3 g and 5 g in urinary protein excretion in 24 h collections were determined by a receiver operating characteristics (ROC) curve.
Results: A highly significant correlation existed between P/Cr in first morning urine samples and urinary protein excretion in 24 h collections. By the ROC curve analysis, the P/Cr of 0.34 g/g and 2.08 g/g in first morning urine samples represented the most appropriate threshold for detecting the urinary protein excretion of 0.3 g and 5 g in 24 h collections.
Conclusion: The P/Cr in spot urine samples can replace urinary protein excretion in 24 h collections. It is a simple and reliable tool of diagnosis and follow-up for preeclampsia.