Accuracy of 12-hour urine collection in the diagnosis of pre-eclampsia.

Objective: To evaluate the accuracy of a 12-hour urine collection to diagnose pre-eclampsia and to determine whether time of collection influences the performance of this test.

Methods: A prospective observational study was conducted in a tertiary obstetric center in Portugal between November 1, 2015, and November 30, 2016. Pregnant women (≥20 weeks) admitted for observation with suspected pre-eclampsia were eligible for inclusion.