Evaluation and Management of Menstrual Irregularities in Adolescence

Initial Clinical Assessment

The initial assessment of menstrual irregularities in adolescents should include a detailed menstrual history, pregnancy testing, and identification of underlying disorders such as PCOS, hypothalamic amenorrhea, or eating disorders, as recommended by the American Academy of Pediatrics 1, 2
A pregnancy test should be performed to rule out pregnancy in any adolescent with missed periods or irregular bleeding, according to the American College of Obstetricians and Gynecologists 2
Assessing for signs of hyperandrogenism and galactorrhea can indicate specific hormonal imbalances, as suggested by the Endocrine Society 2
Reviewing the use of hormonal contraceptives is essential, as they can affect menstrual regularity, as noted by the American College of Obstetricians and Gynecologists 2

Menstrual irregularity is defined as cycles <23 days or >35 days, or absence of bleeding for >6 months, according to the American College of Obstetricians and Gynecologists 1
The World Health Organization defines menstrual irregularity as a variation in menstrual cycle length of more than 7-9 days, as referenced by the Praxis Medical Insights 1

Core hormonal tests, including FSH, LH, prolactin, TSH, and T4, should be obtained strategically to evaluate menstrual irregularities, as recommended by the Endocrine Society 1, 2
Measuring LH and FSH between cycle days 3-6 with three estimations 20 minutes apart can help diagnose PCOS, according to the American Society for Reproductive Medicine 1
Prolactin levels >20 μg/L are abnormal and can cause menstrual irregularity, as noted by the Endocrine Society 1, 2

PCOS is the most common cause of secondary amenorrhea in adolescents, affecting 4-6% of the general female population, as reported by the American College of Obstetricians and Gynecologists 2
Hypothalamic amenorrhea is associated with weight loss, excessive exercise, or emotional stress, and requires treatment priority to increase caloric intake and reduce excessive exercise, as recommended by the American College of Sports Medicine 4

Pelvic ultrasound (transvaginal preferred) should be performed between cycle days 3-9 if ovarian pathology is suspected, as suggested by the American Institute of Ultrasound in Medicine 1, 2
Pituitary MRI is indicated if clinical features or laboratory results suggest hypothalamic-pituitary abnormalities, according to the American College of Radiology 1

Combined oral contraceptives (COCs) provide excellent cycle control for both contraception and medical management of dysmenorrhea, heavy menstrual bleeding, and acne, as recommended by the American College of Obstetricians and Gynecologists 3
Depot medroxyprogesterone acetate (DMPA) is highly effective but causes menstrual irregularities in nearly all patients initially, as noted by the American College of Obstetricians and Gynecologists 5, 7
Levonorgestrel IUD is effective for menstrual suppression in adolescents with complex medical conditions, as reported by the American College of Obstetricians and Gynecologists 5, 7, 8

Referral to endocrinology or gynecology is recommended when amenorrhea persists >6 months, abnormal hormone levels suggest specific pathology, or signs of hyperandrogenism with menstrual irregularity are present, as suggested by the American College of Obstetricians and Gynecologists 2
Infertility concerns or suspected structural abnormalities on imaging also warrant referral, according to the American Society for Reproductive Medicine 1