Hormonal pattern of adolescent menstrual cycles

Area of Science:

• Reproductive Endocrinology
• Adolescent Gynecology

Background:

• Menstrual cycles in adolescents are often irregular and their hormonal profiles are not well-characterized.
• Understanding these hormonal dynamics is crucial for assessing reproductive health in young females.

Purpose of the Study:

• To investigate the hormonal patterns of menstrual cycles in adolescent girls.
• To explore the role of various hormones, including androgens, in adolescent menstrual cyclicity.

Main Methods:

• Radioimmunological measurement of serum hormones including FSH, LH, PRL, estradiol, pregnenolone, progesterone, 17-hydroxyprogesterone, androstenedione, testosterone, 5 alpha-dihydrotestosterone, and androsterone.
• Daily or every-other-day sampling over one menstrual cycle in 20 girls aged 13-17 years.
• Categorization of cycles into three groups based on luteal phase duration, progesterone levels, and hormonal fluctuations.

Main Results:

• Three distinct hormonal patterns were observed, correlating with gynecological age.
• Older adolescents (mean age 2.9 yr) exhibited robust luteal phases with significant progesterone and testosterone rises correlating with LH surge.
• Younger adolescents (mean age 1.5 yr) showed shorter luteal phases and lower testosterone, while anovulatory cycles (mean age 1.1 yr) were characterized by low progesterone and sometimes elevated androgens.

Conclusions:

• Adolescent menstrual cycles display significant hormonal variability.
• Androgens, in addition to gonadotropins, estradiol, and progesterone, may play a role in the development and maintenance of normal menstrual function.
• The hormonal profile evolves with gynecological age during adolescence.