The urinary protein-to-creatinine ratio in Canadian women at risk of preeclampsia: does the time of day of testing matter?

Objectives: To determine the performance of a protein-to-creatinine ratio threshold of 30 mg/mmol in pregnant women investigated for hypertension according to the time of day of the sample.

Methods: This prospective study included ambulatory pregnant women investigated for hypertensive disorders. A single voided random urine specimen was obtained to determine the protein-to-creatinine ratio, followed immediately by a 24-hour urine collection.