What is the most appropriate time to collect urine for pregnancy testing?

The most appropriate time to collect urine for pregnancy testing is the first urine of the day. This is primarily because this sample typically has the highest concentration of the hormone human chorionic gonadotropin (hCG), which is produced during pregnancy. During the night, when the person has not consumed any fluids, the urine becomes more concentrated; thus, if pregnancy has occurred, hCG levels will be more easily detected in the first morning urine.

Other sampling times, such as a random urine sample, may yield less reliable results due to dilution from recent fluid intake or variations in hCG levels throughout the day. Collecting urine after drinking a large amount of water might lead to a more diluted sample, potentially missing low levels of hCG. Similarly, collecting a sample before meals may not ensure that the urine is adequately concentrated for accurate testing. Therefore, the first urine of the day remains the best choice for reliable pregnancy testing.