Random protein-creatinine ratio for the quantitation of proteinuria in pregnancy

To compare random urine protein-creatinine ratios with 24-hour urine protein excretion rates in patients hospitalized with hypertensive disorders in pregnancy.

All hospitalized, hypertensive patients requiring 24-hour urine protein excretion collections were eligible for the study. During the 24-hour urine collection a separate 2-mL aliquot was taken for a protein and creatinine determination.

Seventy-one samples were collected from patients with the following diagnoses: gestational hypertension (n = 56), preexisting hypertension and superimposed gestational hypertension (n = 11), and syndrome of hemolysis, elevated liver enzymes and low platelets (n = 4). The correlation coefficient between the random protein-creatinine ratio and the 24-hour urine protein excretion was 0.94. Calculated excretion rates with at least 300 mg protein in 24 hours had a sensitivity of 0.93, specificity of 0.90, and positive and negative predictive values of 0.87 and 0.95, respectively. For those samples with calculated excretion rates at least 5 g protein in 24 hours, the sensitivity was 1.00, specificity was 0.99, and positive and negative predictive values were 0.75 and 0.99, respectively.

In nonambulatory hypertensive pregnant patients, there is a strong correlation between random voided protein-creatinine ratios and 24-hour urine protein excretions.