Abnormal Uterine Bleeding in Adolescents

March 11, 2018

A female’s first menstrual cycle is an important event during adolescence. For most girls, it marks completion of puberty and the onset of reproductive capability. Menstrual problems are common during adolescence and can last 2-5 years after their first period.


Menstrual irregularities are a common gynecologic problem, especially in adolescents. Abnormal uterine bleeding is any form of bleeding that is irregular in amount, duration, or frequency. It can be characterized by excessive uterine bleeding that occurs regularly, by heavy bleeding at irregular times, or a combination of both. It can also be intermittent bleeding or sparse cyclical bleeding. Often the bleeding is not serious, but it can be annoying and disrupt life. The term ‘dysfunctional uterine bleeding’ is a subset of abnormal uterine bleeding and is defined as excessive, prolonged, or unpatterned bleeding from the uterus without an organic cause,  The term is frequently used synonymously with anovulatory bleeding (irregular bleeding resulting from the absence of ovulation). In adolescents, up to 95% of abnormal uterine bleeding is ‘dysfunctional uterine bleeding’. However, because ‘dysfunctional uterine bleeding’ is a diagnosis of exclusion, other potential causes of abnormal bleeding must be considered and excluded.


You may have abnormal uterine bleeding if you have one or more of the following symptoms:

  • You get your period more often than every 21 days or farther apart than 35 days. A normal adult menstrual cycle is 21 to 35 days long. A normal teen cycle is 21 to 45 days.
  • Your period lasts longer than 7 days (normally 4 to 6 days).
  • Your bleeding is heavier than normal.

(If you are passing blood clots and soaking through your usual pads or tampons each hour for 2 or more hours, your bleeding is considered severe and you should call your doctor.)


The normal menstrual cycle usually consists of an average interval of 28 days (± 6 days) with a average duration of 4 days (±2-3 days). Normal blood loss is approximately 30 mL per cycle, with an upper limit of 60-80 mL. The average age of a first period in the United States is 12.8 years, with the range from 9-18 years.


The normal menstrual cycle is divided into three phases. In the first phase, a group of eggs are stimulated to grow in the ovaries, from which one dominant follicle (egg) is selected. The dominant follicle produces increasing amounts of estrogen. Estrogen stimulates the uterine lining to proliferate and develop progesterone receptors. When estrogen reaches a certain sustained level, a surge of hormone is released from the pituitary, causing the dominant follicle to ovulate:  the second stage of the menstrual cycle. Progesterone halts uterine lining growth and stabilizes the lining, which is the third phase. In the absence of conception, there is a rapid decline in estrogen and progesterone. The endometrium collapses and sheds as menstruation occurs, approximately 14 days after ovulation. Menstrual flow stops as a result of the combined effect of prolonged vasoconstriction, tissue collapse, vascular stasis, and estrogen-induced “healing”.


In summary, with normal ovulation, there is regular cyclical production of estradiol, initiating ovarian follicular growth and uterine proliferation. Following ovulation, the production of progesterone stabilizes the uterine lining. Without ovulation and subsequent progesterone production, a state of “unopposed” continuous estrogen secretion occurs. This stimulates abnormal uterine lining growth without adequate structural support. The consequence is spontaneous sloughing of the endometrium and unpredictable bleeding. In anovulatory cycles, the estrogen levels can either be high or low. With chronic high levels, there is intermittent heavy bleeding, and chronically low levels may result in prolonged light bleeding.[5]


Abnormal uterine bleeding in adolescents is defined as excessive bleeding occurring between menarche (first period) and 19 years of age. During the first 12–18 months after the onset of menstruation, immaturity of the hypothalamic-pituitary axis.  This means that the communication system between the brain, the ovaries and the uterus is immature and not yet communicating properly.  It is believed that this ‘miscommunication’ results in an inconsistent ‘positive feedback’ response, wherein sustained elevations of estrogen occur – which causes progesterone disregulation and prevents ovulation.  The lack of ovulation (called anovulation) is the most common cause of abnormal uterine bleeding during early adolescence. By the third year after menarche, about 75% of menstrual cycles are 21–34 days long, regardless of age at menarche.  The maturation of the hypothalamic-pituitary-ovarian axis occurs slowly in the first 18-24 months after menarche in the adolescent female. Anovulatory cycles may last up to 5 years.


Besides physiologic causes, anovulation can also have organic pathologic causes. These include hyperandrogenic states (e.g., polycystic ovary syndrome [PCOS]), hypothalamic dysfunction (e.g., anorexia nervosa and excessive exercise), endocrinopathies, and premature ovarian failure. Occasionally, the bleeding is caused by an anatomic cause (e.g., polyps or fibroids), although this is very rare in adolescents.


Girls and adolescents with more than 45 days between menstrual cycles, less than 21 days between menses, bleeding lasting longer than 7 days, having a single episode of 3 months between bleeding, or changing sanitary products more often than every 1-2 hours should undergo an evaluation. Regardless of reported sexual history, it is imperative to rule out pregnancy, sexual trauma, and sexually transmitted infections. Patients should be evaluated for endocrine disorders (such as thyroid disease), stress and eating disorders, and polycystic ovary syndrome (PCOS).


Differential Diagnosis of Abnormal Uterine Bleeding in Adolescents


Although the majority of adolescents with abnormal bleeding have anovulation due to age, dysfunctional vaginal bleeding is a diagnosis of exclusion.


Coagulation Disorder

Blood loss in the normal menstrual cycle is self-limited due to the action of platelets and fibrin. Individuals with thrombocytopenia or coagulation deficiency may have excessive menstrual bleeding.The most common coagulation disorders include thrombocytopenia, due to idiopathic thrombocytopenic purpura (ITP), von Willebrand’s disease, which affects up to 1% of the population, and platelet function defects. Of the adolescents presenting with severe menorrhagia or hemoglobin less than 10 g/dL, 25% were found to have a coagulation disorder. In those presenting with menorrhagia at the first menses, 50% were found to have a coagulation disorder.


Pregnancy Complications

The possibility of pregnancy should be considered in any adolescent with abnormal bleeding, and a pregnancy test is mandatory even if the client denies sexual intercourse. Any bleeding in early pregnancy should lead to suspicion of miscarriage or ectopic pregnancy.


Reproductive Tract Pathology

Any trauma, infection, or neoplasm can cause abnormal uterine bleeding. Infections, such as chlamydia or pelvic inflammatory disease (PID), may present with abnormal bleeding. Vaginal trauma or a foreign body may cause bleeding that might be assumed by the adolescent to be uterine in origin. Women with a foreign body in the vagina generally present with a bloody, odorous discharge. Cervical polyps, cervical carcinoma, and cervical inflammation can cause bleeding. Cervical cancer is fairly rare in adolescents but may be encountered in those who had sexual experiences at a very early age (including those with a history of sexual abuse). Ovarian estrogen-producing tumors need to be excluded in the adolescent with very heavy persistent bleeding. Finally, although rare, uterine pathology, such as polyps and fibroids, may lead to abnormal bleeding.



The most common endocrine disorder to cause abnormal bleeding is thyroid disease. In general, hypothyroidism presents with hypermenorrhea, and hyperthyroidism presents with hypomenorrhea. Hyperprolactinemia caused by a prolactinoma or certain medications, such as neuroleptics, can also cause anovulation and abnormal uterine bleeding. PCOS is underdiagnosed in adolescents and should be suspected in obese teens with hirsutism, acne, and continued irregular cycles. There is some recent evidence that PCOS is more common in women with epilepsy. Other diseases to consider are congenital adrenal hyperplasia, Cushing syndrome, hepatic dysfunction, and adrenal insufficiency.


Others Causes

Other causes of abnormal uterine bleeding in adolescents are eating disorders, stress, excessive exercise, and weight loss. In addition, common medications, which increase the cytochrome P450 enzymatic processes in the liver, may induce the more rapid metabolism of steroid hormones, thereby decreasing their bioavailability and result in abnormal uterine bleeding that is secondary to a relative insufficiency of estrogen or progesterone (e.g., anti-seizure medications).


Evaluation and Management of Abnormal Uterine Bleeding in Adolescents


Laboratory testing should initially include an assessment of urine or serum β-hCG, a complete blood count with platelets, and TSH. Other testing should be performed based on the history and physical examination, and may include androgen levels (free or total testosterone) and prolactin. Adolescents with abnormal uterine bleeding can have a concomitant bleeding disorder. Von Willebrand disease is the most common bleeding disorder in women. Approximately one quarter of adolescents who require hospitalization or blood transfusion may have a coagulopathy. Anemia on initial evaluation should trigger further testing for a bleeding disorder including PT, PTT, and a Von Willebrand panel.


The goal of therapy is to decrease excessive bleeding, prevent its recurrence, and improve quality of life. A trial of combined oral contraceptives can serve as a diagnostic and therapeutic approach to the workup of abnormal bleeding in adolescents. In addition to regulating menstrual flow and providing contraception, combined oral contraceptives can provide relief of associated dysmenorrhea, acne/hirsutism, and premenstrual syndrome, prevent menstrual migraine, and potentially reduce pelvic pain associated with endometriosis. In patients who cannot use estrogen due to other existing medical conditions, Depo-Provera or a progesterone-containing IUD can also reliably provide relief for abnormal bleeding, with a substantial proportion of users achieving amenorrhea within 6 months. Rarely, incessant bleeding can become a medical emergency that requires hospitalization and more intense evaluation including a pelvic exam, ultrasound, and treatment including intravenous estrogen, fibrinolytics, and in rare cases, surgical intervention.


Consider coming in for evaluation if you have had irregular vaginal bleeding for three or more menstrual cycles, or if your symptoms are affecting your daily life. There are many things we can do to treat abnormal uterine bleeding. Some are meant to return the menstrual cycle to normal. Others are used to reduce bleeding or to stop monthly periods. Each treatment works for some women but not others. We will discuss all the options and find a treatment that is right for you.


Differential Diagnosis of Abnormal Uterine Bleeding in Adolescents

  • Immaturity of the HPO axis
  • Coagulation disorders

  Idiopathic thrombocytopenic purpura (ITP)

  Von Willebrand’s disease

  Platelet function defect

  • Pregnancy complications

  Abortion (complete, incomplete, missed)

  Ectopic pregnancy

  Trophoblastic disease

  • Genital tract infection



  Vaginal foreign body



  • Endocrinopathies

  Polycystic ovary disease


  Thyroid or adrenal abnormalities

  Premature ovarian failure

  Hypothalamic dysfunction

  Anorexia, stress, excessive exercise

  • Benign lesions of the genital tract

  Cervical polyp

  Vaginal adenosis


  Uterine fibroid

  • Iatrogenic: drugs or hormones
  • Trauma
  • Malignant lesions of the genital tract

Vaginal carcinoma

 Cervical carcinoma

  Uterine carcinoma

  Ovarian tumors