Objective: To examine the role of sexual intercourse as a cause of proteinuria, and establishes its duration, as a knowledge of benign causes of proteinuria is required to avoid unnecessary testing.
Subjects and methods: Twenty-four married couples were instructed to produce a urine sample before and after sexual intercourse; their urine was tested for proteinuria by dipstick analysis.
Results: Samples were assayed from 22 men and 11 women. Whereas none of the 24 men originally assessed for the study had proteinuria before sexual intercourse, six of the 22 who were eventually enrolled had proteinuria after intercourse (27.3%, 95% confidence interval, 10-50%; P = 0.008). None of the women had proteinuria after sexual intercourse (95% confidence interval, 70-100%). The time to disappearance of proteinuria was <12 h.
Conclusion: Sexual intercourse is confirmed as a benign cause of proteinuria in men. Whenever possible, it is wise to avoid sexual intercourse at least 12 h before urinary dipstick testing.