Objectives: Detecting proteinuria is an integral part in management of hypertensive pregnant women. The measurement of protein excretion in a 24-hour urine collection is used as the gold standard for the diagnosis and follow-up of pathologic urinary excretion. However, 24-hour urine collection is time consuming, cumbersome and often inaccurate especially during pregnancy. Pregnant women find it very inconvenient and difficult.
Aim: The study was undertaken to validate the prediction of 24-hour protein excretion by a single voided urine protein-to-creatinine ratio in hospitalized hypertensive pregnant women.
Material and methods: The study was performed in the Pregnancy Pathology Ward, City Hospital in Gdynia in 2002-2004. Pregnant women at > or = 20 weeks with hypertension (blood pressure > or = 140/90 mmHg) with proteinuria at initial urine examination were evaluated. A protein-to-creatinine ratio was obtained from first voided urine sample next morning and then urine was collected for next 24 hours for measurement of protein excretion.
Results: 44 women were evaluated. A total of 56 cases of the 24-hour urine collection were analyzed. There is a close correlation between the protein-to-creatinine ratio in random urine samples and the 24-hour protein excretion measured by 24-hour urine collection. Pearson correlation coefficient R=0,85 (P<0,001, R2= 0,73). A protein-to-creatinine ratio < 0,2 (g/g) can rule out significant proteinuria (defined as 24-hour urinary protein excretion > 300 mg) with sensitivity 92,0%, specificity 90,32%, positive predictive value 88,46%, negative predictive value 93,33%.
Conclusions: The protein-to-creatinine ratio of a single urine sample correlate with the 24-hour urine protein excretion. A protein-to-creatinine ratio < 0,2 (g/g) can rule out significant proteinuria.