Nl. Meyer et al., URINARY DIPSTICK PROTEIN - A POOR PREDICTOR OF ABSENT OR SEVERE PROTEINURIA, American journal of obstetrics and gynecology, 170(1), 1994, pp. 137-141
OBJECTIVE: Our purpose was to compare urinary protein dipstick Values
with standard 24-hour urinary protein excretion in women with hyperten
sion in pregnancy. STUDY DESIGN: Urinary protein dipstick determinatio
ns and concurrent 24-hour urinary protein excretion measurements were
compared by review of 300 urine samples obtained from women with hyper
tension in pregnancy. RESULTS: One hundred twenty-three samples had ne
gative to trace protein on dipstick on two occasions at least 6 hours
apart. Eight-one (66%) of these patients had significant proteinuria (
greater than or equal to 300 mg per 24 hours). Seventy-six samples rev
ealed 3+ to 4+ protein on dipstick in at least two samples. Of these,
27 (36%) had heavy proteinuria (greater than or equal to 5 gm per 24 h
ours), and 42 (55%) had nephrotic range proteinuria of greater than or
equal to 3.5 gm per 24 hours. One hundred one patients had urine dips
tick values of 1+ to 2+, of whom 89 (88%) had significant proteinuria.
CONCLUSION: Urinary protein dipstick values greater than or equal to
1+ have a positive predictive value of 92% (162/177) for predicting gr
eater than or equal to 300 mg per 24 hours. In contrast, a dipstick of
negative to trace should not be used to rule out significant proteinu
ria because its negative predictive value is only 34% (42/123) in hype
rtensive patients. Moreover, urine dipstick Values of 3+ to 4+ should
not be used to diagnose severe preeclampsia because their positive pre
dictive Value is only 36% (27/76).