Objective: Our objective was to determine the frequency of ovulatory salivary progesterone levels before menarche in healthy girls.

Design: We recruited a prospective cohort of midpubertal, premenarcheal girls. Participants collected weekly saliva samples until first menses or for 12 months. Menstrual cycles were considered to have ovulatory salivary progesterone levels if values were greater than 0.100 ng/ml (0.318 nmol/liter) 0-14 d before menarche.

Settings: Participants collected saliva samples weekly at home and attended monthly clinic visits.

Patients: Patients included 63 premenarcheal females, age 9-15 yr, with body mass index higher than the fifth percentile for age and Tanner stage III or greater for both pubic hair and breast development.

Main outcome measures: Frequency of ovulatory levels of salivary progesterone before menarche was assessed.

Results: Fifty-five girls completed the study, and 43 experienced menarche. Of the 42 girls who reached menarche and provided a sample within 14 d of menarche, five (12%) had ovulatory progesterone levels. The mean anovulatory salivary progesterone level was 0.041 ng/ml (0.130 nmol/liter; range, 0.012-0.078 ng/ml, 0.038-0.248 nmol/liter), and the mean ovulatory level was 0.194 ng/ml (0.617 nmol/liter; range, 0.125-0.343 ng/ml, 0.398-1.09 nmol/liter). The levels of estrogen, testosterone, and 17-hydroxyprogesterone were higher and the mean BMI was lower in those with ovulatory progesterone levels vs. those with anovulatory levels.

Conclusion: A significant proportion of girls displayed ovulatory levels of progesterone before menarche. More research is needed to clarify the hormonal events that occur in the perimenarcheal time period.