In the case of pregnancy, the body produces the so-called pregnancy hormone hCG (human chorionic gonadotropin). As pregnancy progresses, the levels of this hormone in the urine begin to increase. In non-pregnant women, the concentration of the hCG hormone is usually 5.0mIU/ml, while when there is a delay in the period, the hCG levels are approximately 100 mIU/ml with peak levels of 100,000 to 200,000 mIU/ml. The First Step® is a rapid pregnancy test that uses chromatographic immunoassay to detect the presence of the hCG hormone in urine for the early detection of pregnancy.