1 What is the average age at menarche? Describe the normal menstrual cycle

The average age at menarche is 12.7 years, with a normal range of 11–14 years. Typically, it occurs approximately 2 years after thelarche and 1 year after peak height velocity.

One menstrual cycle is the time between the onset of one menses to the onset of another. Normal cycle length varies (21–45 days in teens), lasts from 2–8 days, and results in an average blood loss of 30–40 mL. Clinically, the menstrual cycle is usually defined by the ovarian cycle, which includes the follicular, ovulatory, and luteal phases.

During the follicular phase (7–22 days), low levels of estradiol and progesterone result in elevated gonadotropin-releasing hormone levels and, thus, rises in both follicle-stimulating hormone (FSH) and luteinizing hormone (LH). FSH stimulates the maturation of one follicle, while LH stimulates the theca cells to produce androgens, which are converted to estrogens that stimulate proliferation of the endothelium. As estradiol levels rise, FSH levels begin to fall. During the ovulatory phase, a preovulatory estradiol surge causes an LH surge, resulting in release of the ovum. During the luteal phase, the corpus luteum produces large amounts of progesterone and estrogen, resulting in development of the secretory endometrium. If fertilization does not occur, involution of the corpus luteum occurs, and there is loss of estrogen and progesterone. Sloughing of the endometrium follows, and increased levels of FSH lead to a new cycle.

Adams Hillard PJ, Dietch HR: Menstrual disorders in the college age female. Pediatr Clin North Am 52:179–198, 2005.

Gordon CM, Neinstein LS: Normal menstrual physiology. In Neinstein LS (ed). Adolescent Health Care: A Practical Guide, 4th ed. Baltimore, Williams & Wilkins, 2002, pp 947–952.

2 What is dysfunctional uterine bleeding (DUB)?

DUB is excessive menstrual bleeding occurring during the menses or outside the normal intervals in the absence of underlying structural abnormalities. An orderly sequence of hormonal and endometrial events is responsible for the regular and limited bleeding that occurs in adult women. In adolescents, the most common cause of DUB results from anovulatory menstrual cycles due to “immaturity” of the hypothalamic–pituitary–ovary axis, with lack of normal negative feedback. During anovulatory cycles, estrogen levels are increased without increasing FSH responsible for subsequent fall in the estrogen level. Lack of progesterone normally produced by the corpus luteum, which stabilizes the endometrium, results in sporadic growth and slough of the endometrium. In adolescents, it may be more useful to think of this as anovulatory uterine bleeding because this term reflects the most common etiology in adolescents.

Adams Hillard PJ, Dietch HR: Menstrual disorders in the college age female. Pediatr Clin North Am 52:179–198, 2005.

Mitan LA, Slap GB: Dysfunctional uterine bleeding. In Neinstein LS (ed). Adolescent Health Care: A Practical Guide, 4th ed. Baltimore, Williams & Wilkins, Baltimore, 2002, pp 966–972.

3 List the causes of abnormal vaginal bleeding in the adolescent female

Although anovulation is the most common cause of dysfunctional vaginal bleeding in the adolescent, it remains a diagnosis of exclusion. The diseases listed in Table 28-1 must be considered when excessive vaginal bleeding is present.

Table 28-1 Causes of Abnormal Bleeding in the Adolescent Female

4 How should a clinician evaluate a patient to determine a source of vaginal bleeding?

After a careful physical examination, include a pelvic examination to evaluate the source of the bleeding and any pathology. Screens for sexually transmitted diseases (STDs), a pregnancy test, and a serum hemoglobin are useful. In the young teenager who is not sexually active and has mild symptoms, a pelvic examination may be deferred. As always, follow-up is an important part of patient care.

Adams Hillard PJ, Dietch HR: Menstrual disorders in the college age female. Pediatr Clin North Am 52:179–198, 2005.

Mitan LA, Slap GB: Dysfunctional uterine bleeding. In Neinstein LS (ed): Adolescent Health Care: A Practical Guide, 4th ed. Baltimore, Williams & Wilkins, 2002, pp 966–972.

5 What are the recommended therapies for dysfunctional uterine bleeding?

Patients with DUB present with a wide spectrum of severity of illness. Therapy is aimed at stopping the bleeding by converting the endometrium to the secretory state so that sloughing can occur under controlled conditions, correcting the anemia, restoring normal cyclic bleeding, and preventing recurrence and long-term sequelae of anovulation.

A combination of estrogen and progesterone is needed in patients with active bleeding. Any pill combining 35 or 50 μg of ethinyl estradiol or mestranol and a progestin can be used. Progestin only may be used in patients who are not actively bleeding (Table 28-2).

Table 28-2 Therapies for Dysfunctional Uterine Bleeding

OCP = oral contraceptive pill (combination of estrogen, progesterone, and suggested minimum of 30 μg ethinyl estradiol). Antiemetics are usually needed when higher dose of estrogen is given.

In patients with severe bleeding, attention to the ABCs is necessary with IV access and fluid/blood resuscitation. All patients with active bleeding, low hemoglobin, and change in vital signs require admission for treatment. Evaluation should include coagulation studies. Bleeding usually stops after 24 hours of treatment. Combination pills with a higher dose of estrogen (50 μg of ethinyl estradiol) are the first-line therapy. IV estrogen is reserved for use in unstable patients; pulmonary embolism is associated with this therapy. In patients for whom estrogen is contraindicated, progesterone regimens can be tried. If this fails, other therapies include aminocaproic acid, desmopressin, or surgical curettage.

Mitan LA, Slap GB: Dysfunctional uterine bleeding. In Neinstein LS (ed). Adolescent Health Care: A Practical Guide, 4th ed. Baltimore, Williams & Wilkins, 2002, pp 966–972.

Slap BG: Menstrual disorders in adolescence. Best Prac Res Clin Obstet Gynaecol 17:75–92, 2003.

Strickland JL, Wall JW: Abnormal uterine bleeding in adolescents. Obstet Gynecol Clin North Am 30:321–335, 2003.

6 What is primary dysmenorrhea?

Primary dysmenorrhea is painful menses without associated pelvic disease that typically appears 6–24 months following menarche. Dysmenorrhea typically occurs with ovulatory cycles, which become more frequent as the hypothalamic–pituitary–ovarian axis matures. Two years after menarche, 20–50% of teens have ovulatory cycles. Typical symptoms include crampy, lower abdominal pain beginning a few days before or at the start of the menstrual cycle and last for 1–3 days. Associated symptoms include fatigue, back pain, headache, nausea, vomiting, and diarrhea.

7 What causes dysmenorrhea, and how frequently does it occur?

Dysmenorrhea is caused by prostaglandin E₂ and F_2α. These are produced in higher concentrations in ovulatory cycles during the secretory phase. Locally, prostaglandins cause myometrial contraction; however, when they enter the systemic circulation they can cause fatigue, headache, dizziness, nausea, vomiting, diarrhea, and back pain. Prostaglandin F_2α causes uterine contractions, vasoconstriction, and ischemia. Prostaglandin E₂ causes platelet disaggregation and vasodilation.

8 How common is dysmenorrhea?

It occurs very commonly during adolescence. Half to three-quarters of teens experience dysmenorrhea that affects their daily activities. Fifteen percent of teens describe severe symptoms that incapacitate them for 1–3 days during each menstrual cycle. However, only 15% of teens seek medical care for menstrual pain.

Banikarim C, Middleman AB: Primary dysmenorrhea in adolescents. UpToDate, version 13.3, 2005. www.utdol.com.

Braverman PK, Neinstein LS: Dysmenorrhea and premenstrual syndrome. In Neinstein LS (ed): Adolescent Health Care: A Practical Guide, 4th ed, Baltimore, Williams & Wilkins, 2002, pp 952–963.

9 What is the treatment for primary dysmenorrhea?

Nonsteroidal anti-inflammatory drugs (NSAIDs) are first-line therapy for dysmenorrhea; a majority (70–80%) of patients experience relief with their use. Ibuprofen, naproxen, and naproxen sodium have all been used successfully. The patient should begin the medication at the onset of the premenstrual symptoms or at the onset of menses and continue this for 1–3 days as needed to control symptoms. The patient should use the chosen NSAID for four cycles until treatment failure is considered. A second NSAID can be tried at that time. Mefenamic acid competes with prostaglandin-binding sites, antagonizes existing prostaglandin, and inhibits prostaglandin synthesis and thus may be more effective than other NSAIDs.

If the patient continues with symptoms despite NSAID use, a 3- to 6-month course of oral contraceptive therapy may alleviate dysmenorrhea. Ovulation is suppressed, as are prostaglandin production and menstrual flow.

Patients should be followed closely. If they do not respond to the described therapies, a re-evaluation seeking secondary causes is indicated.

Banikarim C, Middleman AB: Primary dysmenorrhea in adolescents. UpToDate, version 13.3, 2005. Available at www.utdol.com.

Braverman PK, Neinstein LS: Dysmenorrhea and premenstrual syndrome. In Neinstein LS (ed): Adolescent Health Care: A Practical Guide, 4th ed. Baltimore, Williams & Wilkins, pp 952–963.

10 What are the causes of secondary dysmenorrhea?