Most Common Cause of Abnormal Uterine Bleeding in Adolescent Females
Anovulation due to immaturity of the hypothalamic-pituitary-ovarian axis is the most common cause of abnormal uterine bleeding in adolescent females. 1, 2, 3
Pathophysiology
The immature hypothalamic-pituitary-ovarian (HPO) axis in the first 2-3 years post-menarche leads to anovulatory cycles, which account for the majority of dysfunctional uterine bleeding (DUB) cases in this age group 2, 3
Anovulation results in unopposed estrogen stimulation of the endometrium without progesterone-mediated stabilization, causing irregular endometrial breakdown and unpredictable heavy bleeding 4
This physiologic immaturity is a normal developmental process, though a significant number of adolescents may require ongoing gynecologic follow-up for persistent abnormal bleeding 1
Critical Differential Diagnosis
While anovulation is most common, bleeding disorders must be excluded, particularly von Willebrand disease, as approximately 20% of adolescents with heavy menstrual bleeding have an underlying coagulopathy 3:
Bleeding disorders are especially likely when heavy menstrual bleeding has been present since menarche 3
If there is no response to hormonal therapy within 48 hours, reevaluation for coagulopathy is mandatory 5
Primary bleeding disorders typically affect all bleeding episodes (including minor trauma), not just menstrual bleeding 4
Essential Diagnostic Workup
Before diagnosing anovulatory DUB, the PALM-COEIN classification system should guide exclusion of other causes 4, 6:
Pregnancy test (β-hCG) is mandatory in all reproductive-age females 4, 7
Thyroid-stimulating hormone (TSH) and prolactin levels must be measured to exclude hypothyroidism and hyperprolactinemia 4, 3
Hemodynamic stability should be assessed; urgent evaluation is needed if bleeding saturates a large pad/tampon hourly for ≥4 hours 4, 7
Combined transabdominal and transvaginal ultrasound with Doppler is first-line imaging to identify structural causes 7
Management Approach
Combined oral contraceptives are first-line treatment for anovulatory bleeding in adolescents, providing cycle regulation and reducing bleeding 4, 2:
High-dose combination oral contraceptives can achieve rapid hemostasis in acute severe bleeding 5
Iron supplementation should be provided based on degree of anemia 3
NSAIDs and tranexamic acid are alternative or adjunctive options 2
Progestin-only contraception, including levonorgestrel-releasing IUD, is highly effective but may cause irregular bleeding patterns 8, 4
Important Clinical Caveat
Adolescents with persistent anovulation and irregular bleeding after the initial post-menarchal years warrant close follow-up, as this may represent early polycystic ovary syndrome (PCOS) 9: