Hormone assays have been developed and applied for monitoring reproductive function using self‐collected urine samples in non‐clinical populations of women. Early pregnancy loss, menstrual dysfunction, reduced fertility as well as the site of toxicity can now be assessed using daily early morning urine samples. The understanding of the specific limitations of individual assay systems is important, however, to make the best use of these systems. The use of multiple end‐points and computer algorithms is suggested to avoid misclassification of adverse reproductive events.