[Spot urinary protein to creatinine ratio: Which role in preeclampsia diagnosis?]

Preeclampsia remains a serious and feared complication of pregnancy. Its diagnosis is confirmed upon detection of hypertension and significant proteinuria starting from 20 weeks of gestation. The 24-hour urine collection is considered to be the gold standard test for quantitative diagnosis of proteinuria despite its downsides. Recent studies have brought into question its accuracy during pregnancy as complete samples are hard to get, but above all, as this time consuming procedure often delays treatment and may preclude optimal management. Several publications looked at the spot urinary protein to creatinine ratio (PCR) as a replacement to the 24-hour urine collection. Largely used outside pregnancy, this fast and less invasive test seems a compelling alternative. In this paper, data from previous meta-analysis and guidelines have been reviewed in an attempt to clarify the role of the PCR in clinical practice and elaborate an algorithm in case of suspicion of preeclampsia. Thus, this test seems a valid "rule-out test" when using the optimal threshold of 30mg/mmol. Higher values require a 24-hour urine collection for confirmation.