Determination of 17-hydroxyprogesterone in the normal and induced ovulatory cycles

Concentrations of 17-hydroxyprogesterone (170HPg) were measured in serum samples obtained daily through cycles both spontaneous and induced by gonadotropins. These samples had previously been assayed for estradiol, progesterone, luteinizing hormone (LH). The concentration of 170HPg increases considerably the day before the LH peak in the ovulatory cycles. In the anovulatory cycles the 170HPg levels are shown as being low or the constant high levels in one case has not been followed by the LH peak. In our opinion the parameter taken into consideration does not lend itself completely to the prediction of the ovulatory event but in synchronism with the LH peak, may be a useful index of the follicular luteinization both in the spontaneous ovulatory cycles and in the stimulated cycles where the estrogenic increase is abnormal.