FIGURE 28. Control of testosterone production in the human fetus. Note the low testosterone concentration during the last trimester, at the time that hCG production by the placenta has abated. Data obtained from ref. (548): Winter JSD, Faiman C, Reyes F (1981). Sexual endocrinology of fetal and perinatal life. In: Austin CR, ed. Mechanisms of Sex Differentiation in Animals and Man. London: Academic Press; p.205-253.