Accuracy of urinalysis dipstick techniques in predicting significant proteinuria in pregnancy.

OBJECTIVE: To estimate the accuracy of point-of-care dipstick urinalysis in predicting significant proteinuria in pregnancy. DATA SOURCES: Literature from 1970 to February 2002 was identified via 1). general bibliographic databases, that is, MEDLINE and EMBASE, 2). Cochrane Library and relevant specialist register of the Cochrane Collaboration, and 3). checking the reference lists of known primary and review articles. METHODS OF STUDY SELECTION: Studies were selected if the accuracy of dipstick urinalysis techniques in predicting total protein excretion was estimated compared with a reference standard (laboratory estimation of protein excretion). The tests included visually read color-change dipsticks and automated dipstick urinalysis. Study selection, quality assessment, and data abstraction were performed independently and in duplicate. TABULATION, INTEGRATION, AND RESULTS: Data from selected studies were abstracted as 2 x 2 tables comparing the test result with the reference standard. Test accuracy was expressed as likelihood ratios. Summary likelihood ratios were generated as measures of diagnostic accuracy to determine posttest probabilities. The electronic search produced 1543 citations. After independent review of published articles, a total of 34 articles was obtained for further scrutiny, and 7 studies were considered eligible for inclusion in the review. The 6 studies evaluating visual dipstick urinalysis produced a pooled positive likelihood ratio of 3.48 (95% confidence interval 1.66, 7.27) and a pooled negative likelihood ratio of 0.6 (95% confidence interval 0.45, 0.8) for predicting 300 mg/24-hour proteinuria at the 1+ or greater threshold. CONCLUSION: The accuracy of dipstick urinalysis with a 1+ threshold in the prediction of significant proteinuria is poor and therefore of limited usefulness to the clinician. Accuracy may be improved at higher thresholds (greater than 1+ proteinuria), but available data are sparse and of poor methodological quality. Therefore, it is not possible to make meaningful inferences about accuracy at higher urine dipstick thresholds. There is an urgent need for research in this area of common obstetric practice.

Prenatal bladder drainage in the management of fetal lower urinary tract obstruction: a systematic review and meta-analysis.

OBJECTIVE: To estimate the effect of prenatal bladder drainage on perinatal survival in fetuses with lower urinary tract obstruction. DATA SOURCES: Relevant articles were identified by searching the databases MEDLINE (1966-2002), EMBASE (1988-2002), and the Cochrane library (2000;4). METHODS OF STUDY SELECTION: Studies were selected if the effect of prenatal bladder drainage (vesicocentesis, vesicoamniotic shunt, or open fetal bladder surgery) on perinatal survival was reported in fetuses with ultrasonic evidence of lower urinary tract obstruction. Study selection, quality assessment, and data abstraction were performed independently and in duplicate. TABULATION, INTEGRATION, AND RESULTS: Sixteen observational studies that included nine case series (147 fetuses) and seven controlled series (195 fetuses) were identified. Study characteristics and quality were recorded for each study. Data on the effect of bladder drainage on perinatal survival were abstracted. Where controlled data were available, 2 x 2 tables were generated to compare the effects of bladder drainage versus no bladder drainage on perinatal survival. Pooled odds ratios (ORs) were used as summary measures of effect, and the results were stratified according to predicted fetal prognoses (based on ultrasound features and fetal urinary electrolytes). Among controlled studies, bladder drainage appeared to improve perinatal survival relative to no drainage (OR 2.5; 95% confidence interval [CI] 1.1, 5.9; P =.03). However, this observation was largely because among the subgroup of fetuses with a poor prognosis there was a marked improvement (OR 8.1; 95% CI 1.2, 52.9; P =.03). Improved perinatal outcome was also suggested in those fetuses considered to have a good prognosis (OR 2.8; 95% CI 0.7, 10.8; P =.13). CONCLUSION: There is a lack of high quality evidence to reliably inform clinical practice regarding prenatal bladder drainage in fetuses with ultrasonic evidence of lower urinary tract obstruction. The limited available evidence suggests that prenatal bladder drainage may improve perinatal survival in these fetuses, particularly those with poor predicted prognoses. Further research in the form of a multicenter randomized controlled trial is required to assess the short- and long-term effects of this intervention.

Noninvasive techniques to detect fetal anemia due to red blood cell alloimmunization: a systematic review.

OBJECTIVE: To estimate, in maternal red blood cell alloimmunization, the diagnostic value of fetal ultrasonography and Doppler blood flow velocity in the evaluation and prediction of fetal anemia. METHODS: Literature from 1970 to 2000 was identified using general bibliographic databases (MEDLINE and EMBASE), the Cochrane Library and relevant specialist register of the Cochrane Collaboration, and by checking reference lists of known primary and review articles. Studies were selected if the accuracy of the fetal ultrasound parameters or Doppler studies of blood flow in the fetal vessels was estimated compared with a reference standard (fetal hemoglobin). The diagnostic tests evaluated were ultrasound measurement of the fetal spleen perimeter and Doppler studies of blood velocity estimates in the umbilical vein, ductus venosus, middle cerebral artery, thoracic aorta, and umbilical vessel combined with the thoracic aorta. Study selection, quality assessment, and data abstraction were performed independently and in duplicate. Data from the selected studies were abstracted as 2 x 2 tables comparing the diagnostic test result with the reference standard. Diagnostic accuracy was expressed as likelihood ratios. RESULTS: The review included eight primary studies with 362 pregnancies affected by red cell alloimmunization. Prospective patient recruitment and complete population details were reported in half of the selected studies (four of eight). Only one study reported masking the diagnostic test results to clinicians. The diagnostic test performance varied widely according to the type of the test evaluated and the cutoff level used to define fetal anemia, which varied from study to study. The diagnostic test study of highest methodological quality reported a positive likelihood ratio of 8.45 (95% confidence interval 4.69, 15.56) and negative likelihood ratio of 0.02 (95% confidence interval 0.001, 0.25) for maximum middle cerebral artery Doppler velocity. CONCLUSION: The literature reporting noninvasive techniques to predict fetal anemia is methodologically poor and a standard approach to the evaluation of these techniques is lacking. A recommendation for practice cannot be generated without further rigorous research.