Correlation of 4 Hour Urine Samples with 24-Hour Urine Samples for the Diagnosis of Preeclampsia

Background Preeclampsia is one of the causes of maternal and prenatal mortality and morbidity. The 24-hour urine sample is considered as a gold standard for preeclampsia diagnosis and shortening the time of urine collection will result in the patients’ convenience and shorter hospitalization. The goal of this study was to determine thee diagnostic accuracy of 4 hour urine protein in comparison with 24 hour urine protein in pregnant women. Methods One hundred pregnant women, with a gestational age of more than 20 weeks, and were suspicious to preeclampsia were enrolled. The 24-hour as well as the 4-hour urine sample were collected. All data were analyzed using the SPSS software, version 20 (SPSS Inc., Chicago, IL, USA). The correlation coefficient was used to determine relationship between the 4 and 24-hour urine proteins. receiver operating characteristic (ROC) curve was used to determine optimal cut-off values of 4 hour proteinuria. Results The mean age and mean gestational age of participants was 26.8 & 6.1 years and 34.1 & 3.4 weeks. The mean 4-hour urine protein was 165.6 & 170.2 mg and the mean 24 hour urine protein was 926 & 1013 mg. The mean age, 4-hour urine protein, and 4 as well as 24 hour urine volumes were significantly different between cases with no, mild, or severe proteinuria. Pearson correlation coefficient between 4 and 24 hour proteinuria was strong (r = 0.97 and p < 0.001). The best cut off point for 4-hour proteinuria to determine proteinuria was 69.5 mg with a sensitivity of 93% and specificity of 100%. (Area under the curve = 0.99, p < 0.001). Conclusions Women that are suspicious to have preeclampsia, the total 4-hour urine protein values positively correlated with values of 24-hour samples.