Rapid Assays of Urinary Estriol in Pregnant Women

Two devices designed for rapid assay of urinary estriol, the E3 KIT and the E3 HAIR KIT, were evaluated using urine samples taken from pregnant women. Additionally, the clinical application of these devices in pregnancy management was examined. Correlations were high between an established method and the E3 KIT method (r=0.819, p<0.001) and between the E3 HAIR KIT method and the E3 KIT method (r=0.936, p<0.01). E3 HAIR KIT assays showing E3 values of less than 20 μg/ml (positive at 100‐fold dilution of the urine) after the 36th week of pregnancy suggested fetoplacental dysfunction and indicated that more detailed tests were required. The E3 KIT, which provided rapid quantitative assay of urinary estriol, was capable of measuring 10 samples in approximately 3 hours. The E3 HAIR KIT provided semiquantitative assays of 10 samples in 2 hours. The speed, simplicity, and accuracy of the E3 HAIR KIT indicates its high clinical value as a prospective large‐scale screening method for fetoplacental function.