Urine protein-to-creatinine ratio: A point of care for the diagnosis of preeclampsia

BACKGROUND: The aim of this study was to determine the correlation between the urine protein-creatinine ratio (UPCR) and the 24-hour urine protein excretion test (UPET), and to identify the optimal threshold values of UPCR for the diagnosis of preeclampsia and its severe form. METHODS: This prospective cohort study included 81 hypertensive pregnant patients who had a 24-h UPET and a UPCR tests. Two groups were created using a UPCR cut-off of 23.2 mg/mmol (40 negative UPCR, 41 positive UPCR). RESULTS: Forty-nine patients of were diagnosed with preeclampsia, and 23 of them had a severe disease. There was a significant correlation between UPCR and 24-h UPET. A cut-off UPCR value of 23.2 mg/mmol had an area under the curve (AUC) of 0.27, sensitivity of 89%, specificity 88%, positive predictive value 90%, a positive likelihood ratio (+LR) of 7.41 and a negative likelihood ratio (-LR) of 0.13 for the diagnosis of preeclampsia. UPCR value of 325 mg/mmol had an AUC of 0.841, and a sensitivity of 83%, specificity 81%, positive predictive value 81%, +LR of 4.4 and -LR of 0.2 for the diagnosis of severe preeclampsia. CONCLUSIONS: The UPCR test is highly correlated with the 24-h UPET. We propose a novel and sensitive cut-off for the diagnosis of preeclampsia by UPCR test. The UPCR test can be used for the identification of hypertensive patients with preeclampsia and severe disease.