IMPROVED METHODS OF ASSESSING PROTEINURIA IN HYPERTENSIVE PREGNANCY

Objective To determine whether use of an automated urinalysis device w ill improve the accuracy of detecting proteinuria, and whether spot ur ine protein to creatinine ratio will provide accurate quantitation of proteinuria in hypertensive pregnant women. Design Prospective studies assessing the accuracy of both detection and quantitation of proteinu ria. Setting Antenatal ward and pregnancy day assessment unit of St Ge orge Hospital, a teaching hospital in Sydney, Australia. Population Hy pertensive pregnant women admitted to hospital or day assessment unit for management of their hypertensive disorders. Methods 1. Routine dip stick urinalysis and 2. urinalysis by an automated device (Clinitek 10 0 Ames) on a midstream urine sample were compared with measurement of protein concentration on that sample (n = 103). In a third study, the protein:creatinine ratio on a midstream (spot) urine sample was compar ed with protein excretion over the subsequent 24 hours (n = 100). Main outcome measures Relations between urine protein concentrations and 1 . dipstick urinalysis and 2. automated urinalysis; 3. Positive and neg ative predictive values of spot protein:creatinine ratio for true prot einuria (greater than or equal to 300 mgiday). Results Automated urina lysis improved the percentage of true positive urinalyses from 48% wit h visual urinalysis to 74% (P = 0.02). True negatives were 98% to 100% for both methods. Spot urine protein:creatinine ratio correlated well with subsequent 24-hour urine proteinuria (r = 0.93, P < 0.001). A pr otein:creatinine ratio > 30 mg protein/mmol creatinine was the optimum discriminant value for true proteinuria, with sensitivity 93%, specif icity 92%, positive predictive value 95% and negative predictive value 90%. Conclusions Use of an automated urinalysis device improved accur ate detection of proteinuria, particularly reducing false positive tes ts. A random urine protein:creatinine ratio provides an accurate and r apid quantitation of proteinuria in hypertensive pregnant women. This should improve clinical care, especially when managing hypertensive pr egnant women as outpatients.