More than 100 stains of blood from women in all stages of pregnancy, normal menstruation, menopause, and postmenopause were analyzed. Only one centimeter squares of bloodstain were required for the measurement of the levels of the four hormones to indicate the state of pregnancy. The laboratory bloodstains from the 25 non-pregnant women and from the men all yielded negative results. These stains were between 1 and 35 days old. The stains from the nonpregnant women gave positive results except for 5 stains, which came from women 10-18 days pregnant aged between 18 and 36 years. The negative stains were between 3 and 23 days old. In the positive group, 24 second trimester pregnancies and 35 first trimester pregnancies were identified. The women ranged in age between 21 and 38 years, and the stains were between 2 days and 34 months old. Two case examples are described to illustrate the application of this technique to crime scenes investigation. 4 figures, 3 tables, and 10 references (Author abstract modified)