Forensic determination of pregnancy hormones in human bloodstains

When different bloodstains are encountered at the scene of crime, it is possible to discriminate those from a pregnant woman from others. Human chorionic gonadotrophin, human placental lactogen, total oestriol and progesterone in the stains may be determined with radioimmunoassay techniques using commercial kits. Only 1 cm2 of bloodstain is needed for the determination of all four parameters, which gives information about the state of pregnancy. More than 100 stains of blood from women in all stages of pregnancy, normal menstruating women, menopausal and post-menopausal women and male subjects, and of menstrual blood were analysed. Bloodstains from pregnant women were easy to evaluate with the four determinations, only very early pregnancies being undetected. Stains from non-pregnant women were negative or below the cut-off level. Two case examples are also described.