Figure 1.

Reproductive hormone and basal body temperature changes across an ovulatory menstrual cycle. Top panel shows the profile for serum luteinizing hormone (LH) that peaks just before ovulation (dotted line). Middle panel shows fluctuations in serum levels of the ovarian hormones, estradiol, and progesterone across the menstrual cycle. Bottom panel indicates the biphasic curve in morning basal body temperature (oral) across the menstrual cycle. Data from 10 women with ovulatory menstrual cycles [58].