The Role of the Urine Dipstick Test in the Detection of Abnormal Proteinuria Using Different Cut-off Levels in Hypertensive Pregnancies

Abstract

Aim: The aim of this study was to determine the diagnostic accuracy of different urine dipstick protein threshold levels in predicting the presence of abnormal proteinuria in pregnant women with hypertension. Material and Methods: A total of 326 singleton pregnant women who underwent 501 urine protein tests and who had suspected preeclampsia were included in this retrospective study. Patient data was taken including medical and obstetric history. The results of dipstick urinalysis and concurrent 24-hour urine protein excretion measurements were compared to determine the accuracy of urinalysis. Results: A dipstick result of 1+ was found to be the best cut-off to predict 500 mg of protein excretion per day, with sensitivity and specificity of 62.09% and 88.97%, respectively. A 2+ proteinuria dipstick cut-off had high specificity and positive predictive value (PPV) (99.05% and 98.84%, respectively) for the prediction of 300 mg of protein excretion per day; this cut-off had low sensitivity (21.46%). A cut-off of 1+ also provided satisfactory specificity and PPV (91.43% and 94.48%, respectively) for the detection of 300 mg of protein excretion per day, but sensitivity was compromised (38.89%). Among 301 patients with negative dipstick results, 212 had a 24-hour urine protein extraction greater than 300 mg, with a false negative rate of 70.43%. Conclusion: The results suggest that the urine protein dipstick measurement has limited quantitative ability for the prediction of abnormal proteinuria. Additionally, the use of 500 mg 24-hours protein excretion as a cut-off value for abnormal proteinuria may provide useful data.

Keywords

• 24 saatlik idrar proteini
• daldırma çubuğu idrar tahlili
• preeklampsi
• gebelik
• proteinüri
• 24-hour urine protein
• dipstick urinalysis
• preeclampsia
• pregnancy
• proteinuria