A Human Pregnancy Test Based Upon a Color Reaction of Pregnandiol in the Urine1,2

Abstract

IN THE NORMAL human menstrual cycle, pregnandiol is found in the urine from the ninth day until one to four days prior to the onset of bleeding (1–3). The consistency of this finding, in spite of a variable quantitative excretion in any one cycle, has led to an association between pregnandiol and corpus luteum activity. If fertilization occurs and normal pregnancy ensues, then pregnandiol excretion continues at or above the maximum level reached during the latter half of the menstrual cycle. The excretion increases rapidly between the 60th and 90th day of pregnancy, reaches a peak shortly before parturition, and stops 24 to 48 hours after delivery (4–7). Despite quantitative variation in individual cases, this general pattern of pregnandiol excretion persists. In the first two months of pregnancy, progesterone, secreted by the corpus luteum, is probably the chief source of pregnandiol in the urine. The spurt in pregnandiol excretion in the third month, with simultaneous regression of the corpus luteum, is probably due to placental secretion of progesterone or another pregnandiol precursor (8).