Ovarian function in human pregnancy

Free neutral steroids were measured in the ovarian and uterine vein blood during pregnancy. Progesterone concentration ranged from 34μg per 100ml. of whole blood at 8weeks to 63 at 11½weeks and 44 at 19weeks. Lower values were obtained in the later half of pregnancy. No ovarian progesterone was detected 2days post partum. Progesterone concentration of 14.8μg per 100ml. blood was found in uterine vein blood 8weeks following the last menstrual period. Higher values were obtained as pregnancy progressed. Significant amounts of 17α-hydroxyprogesterone, 20α-hydroxy-4-pregnene-3-one and androstenedione were isolated from the ovarian vein blood. In addition to progesterone, only 20α-hydroxy-4-pregnene-3-one was isolated from uterine venous blood. An apparent qualitative similarity was observed between the secretory products of the ovary during pregnancy and the luteal phase of the menstrual cycle.