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

Abstract

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. 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). 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. 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.