In a 14‑year‑old girl with several weeks of continuous vaginal bleeding and a normal coagulation profile (normal INR/PT, platelet count, and clotting factors), what is the most likely diagnosis and recommended management?

Abnormal Uterine Bleeding in a 14-Year-Old with Normal Coagulation

The most likely diagnosis is anovulatory dysfunctional uterine bleeding (ovulatory dysfunction), and first-line treatment is combined hormonal contraception or progestin-only therapy. 1

Diagnostic Framework

In a 14-year-old with persistent bleeding and normal coagulation studies, the PALM-COEIN classification system guides evaluation by distinguishing structural from nonstructural causes. 1 With normal coagulation already confirmed, the "C" (coagulopathy) has been excluded, making ovulatory dysfunction the predominant consideration in this age group. 1

Why Anovulation is Most Likely

• Adolescence is a physiologic cause of anovulation due to immaturity of the hypothalamic-pituitary-ovarian axis in the first 1-2 years after menarche. 1, 2
• Anovulatory bleeding characteristically presents as irregular, prolonged episodes without signs of ovulation (no midcycle pain, premenstrual symptoms, or regular intervals). 3, 2
• The chronic unopposed estrogen from anovulation causes continuous endometrial proliferation, resulting in unstable endometrium that bleeds irregularly. 3

Critical Exclusions Already Addressed

• Pregnancy complications must always be excluded first in any reproductive-age female with abnormal bleeding, requiring beta-hCG testing. 1, 4
• Coagulopathy screening is essential in adolescents with menorrhagia, as von Willebrand disease and other bleeding disorders are more common than recognized. 4 However, your patient's normal coagulation profile has already ruled this out.
• Other causes to exclude include thyroid disease (TSH), hyperprolactinemia (prolactin level), and hyperandrogenic conditions. 1

Recommended Management Algorithm

First-Line Medical Treatment

Combined hormonal contraception or progestin-only contraception are the ACOG-recommended first-line treatments for abnormal uterine bleeding associated with ovulatory dysfunction. 1

For acute bleeding control:

• High-dose estrogen therapy or combined oral contraceptives can stop acute bleeding episodes. 3
• Progestational agents (oral or intramuscular) are effective for stopping acute bleeding and preventing future episodes. 3

For long-term cycle regulation:

• Monthly courses of medroxyprogesterone acetate 10 mg daily for 10 days each month provide cycle regulation. 2
• Continuous combined hormonal contraception offers both contraception and cycle control. 2

When to Escalate Evaluation

If medical treatment fails, is not tolerated, or bleeding persists, further investigation with imaging is mandatory. 1

• Transabdominal ultrasound is preferred in adolescent virgins rather than transvaginal approach. 1
• Saline infusion sonohysterography has 96-100% sensitivity for detecting intracavitary pathology if ultrasound is inconclusive. 1
• Endometrial biopsy is generally not indicated in adolescents unless there are risk factors for malignancy or hyperplasia (obesity, chronic anovulation, failed medical therapy). 1

Surgical Options (Rarely Needed in Adolescents)

Surgery including endometrial ablation or hysterectomy may be considered only if medical treatment fails, is contraindicated, or if significant intracavitary lesions are identified. 1 These are extremely uncommon interventions in a 14-year-old and would require subspecialty consultation.

Common Pitfalls to Avoid

• Never assume dysfunctional bleeding without excluding structural pathology if the patient fails to respond to appropriate hormonal therapy. 1, 3
• Do not overlook coagulopathy screening in adolescents with heavy bleeding, though this has been appropriately done in your patient. 4
• Avoid endometrial sampling as a first-line test in adolescents unless there are specific risk factors for endometrial pathology. 1
• Recognize that anovulatory bleeding in adolescence is physiologic but still requires treatment to prevent anemia and improve quality of life. 1, 2

Monitoring and Follow-Up

• Track response to hormonal therapy within 1-3 cycles. 3
• Reassess if bleeding persists despite appropriate medical management, as this suggests either non-compliance, incorrect diagnosis, or presence of structural pathology. 1, 3
• Monitor hemoglobin if bleeding has been prolonged to assess for anemia. 4