PERIOVULATORY LEVELS OF PLASMA PROGESTERONE AND LUTEINIZING HORMONE IN WOMEN

ABSTRACT Plasma LH and progesterone levels were measured around the time of ovulation in 16 normal menstrual cycles. No increased levels of progesterone were found before the LH peak. The maximal LH peak levels lasted for 16–20 h at which time the plasma progesterone rose to a concentration of 1 to 2 ng/ml. Following the fall in the LH concentration, there was a rapid rise in the plasma progesterone concentration, indicating the formation of a corpus luteum. The lowest basal body temperature coincided with the first significant rise in LH levels.