Diagnostic Accuracy of Urinary Protein/Creatinine Ratio versus 24-Hour Urinary Protein in Evaluating PreEclampsia and Perinatal Outcomes: A Comparative Study

Abstract

Background: Pre-eclampsia remains a leading cause of maternal and perinatal
morbidity and mortality. Accurate and timely diagnosis is crucial for preventing
adverse outcomes. Although the 24-hour urinary protein excretion is considered the
gold standard for assessing proteinuria, it is cumbersome and time-consuming. The
spot urine protein-to-creatinine ratio (UPCR) offers a simpler, quicker alternative.
This study aims to evaluate the diagnostic accuracy of UPCR compared to 24-hour
urinary protein estimation and to examine its association with perinatal outcomes.
Methods: A prospective observational study was conducted at Gauhati Medical
College and Hospital, Assam, between September 2022 and October 2023. A total of
102 pregnant women with suspected pre-eclampsia were enrolled. Both 24-hour
urinary protein levels and UPCR were measured, and outcomes were assessed.
Diagnostic performance was evaluated using sensitivity, specificity, positive
predictive value (PPV), and negative predictive value (NPV).
Results: UPCR demonstrated a high sensitivity of 92.9% and specificity of 84.6% in
detecting significant proteinuria when compared to 24-hour urinary protein. The PPV
was 97.2%, while the NPV was 64.7%. A strong correlation was observed between
UPCR and adverse perinatal outcomes such as low birth weight, NICU admission,
and preterm delivery.
Conclusion: The UPCR is a reliable, rapid, and patient-friendly alternative to 24-
hour urinary protein measurement for diagnosing proteinuria in pre-eclampsia. It
shows strong diagnostic accuracy and can aid in early intervention. However, its
lower NPV warrants cautious interpretation in exclusion scenarios.