Correlation of Urine Protein Values in 8 and 16-Hour with 24-Hour Samples to Diagnose Pre-Eclampsia

Proteinuria is one of the most important signs of pre-eclampsia. A 24-hour urine collection is the gold standard for determining urinary protein. Considering the difficulty and costly of this test، many studies have been done to find easier and faster methods. The aim of this study was to survey the relationship of 8 and 16-hour urinary protein values with 24-hour urinary protein values in hypertensive pregnant women to diagnose pre-eclampsia. This cross sectional study was conducted on 184 pregnant women who were hospitalized to determine preeclampsia in Imam Reza hospital، Mashhad، Iran، 2008. Cases were divided into two groups of 92 pregnant women with normal blood pressure and 92 women with high blood pressure. Within a 24- hour period، three 8-hour urine samples were collected in separate containers consecutively and urine volume، protein and creatinine value were measured. Sensitivity، specificity، positive and negative predictive values and Pearson correlation coefficients of urinary protein values were assessed for first and third 8-hour and 16- hour. Data were analyzed using statistical SPSS software version 16، and paired t-test، independent t-test and Leven test. P value less than 0. 05 was considered significant. In hypertensive patients، first 8-hour sample had sensitivity of 58. 8%، specificity of 92%، positive and negative predictive value 62. 5% and 90. 8%، respectively. The 16- hour sample had sensitivity of 76. 5%، specificity of 96%، positive and negative predictive value 81. 3% and 94. 7%، respectively. The correlation coefficients of first 8-hour and16-hour with 24-hour urinary protein were 0. 621 and 0. 832، respectively. There were strong positive correlation between urinary samples 16-hour and moderate positive correlation between first and third 8-hour with values of 24-hour samples. Short collecting of urine had more diagnostic value in rule out of pre-eclampsia.