Some of the most visible changes during puberty are growth in stature and development of secondary sexual characteristics.1 Other significant changes include body composition, the achievement of fertility, and changes in various body systems.1
Normal Puberty in Girls
Changes in hypothalamic-pituitary-gonadal endocrine function lead to the obvious changes associated with secondary sexual development. Endocrine changes of puberty are divided into two distinct phases.1 First is gonadarche, or the activation of gonadal action during which increased pituitary gonadotropins cause the secretion of gonadal steroids.1 Second is adrenarche, or the activation of the adrenal androgen secretion caused by various factors that are not fully understood.1
Stages of pubertal development are described using a sexual maturity rating scale called Tanner stages.2 Staging provides an objective and consistent description of physical development. Breast development, which is caused by ovarian estrogens, and pubic hair development, which is caused by adrenal androgens, are usually coordinated in girls but not always. When these are not synchronized, premature adrenarche or premature thelarche may ensue.2 Therefore, each of these stages should be documented to ensure appropriate development is underway for a patient.
Menstruation is the shedding of the lining of the uterus, called the endometrium, which is then accompanied by bleeding.2 It occurs in approximately monthly cycles throughout a woman's reproductive life, except during pregnancy. Menstruation starts during puberty at menarche and stops permanently at menopause.2
The menstrual cycle begins with the first day of bleeding, which is counted as the first day of the monthly cycle.3 The cycle ends just before the next menstrual period. Menstrual cycles normally range from about 25 to 36 days, and only 10% to 15% of women have cycles that are exactly 28 days.3 It is also known that at least 20% of women have irregular cycles, which means that they can be longer or shorter than the normal range.3 Cycles tend to vary the most and the intervals between periods are longest in the years immediately after menarche and before menopause.3
Menstrual bleeding lasts 3 to 7 days, with an average length of 5 days.3 The usual blood loss during a cycle ranges from 0.5 to 2.5 ounces.3 A sanitary pad or tampon can hold up to 5 mL of blood. Menstrual blood, unlike blood resulting from an injury, usually does not clot unless the bleeding is heavy.3
The menstrual cycle is regulated by hormones called luteinizing hormone and follicle-stimulating hormone, which are produced by the pituitary gland.2 These hormones promote ovulation and stimulate the ovaries to produce estrogen and progesterone.2 Estrogen and progesterone stimulate the uterus and breasts to prepare for possible fertilization.2
The menstrual cycle has three phases. The first is the follicular phase before release of the egg, the second is the ovulatory phase when the egg is released, and the third is the luteal phase, which occurs after the egg is released.2 Menstrual flow marks the first day of the follicular phase.2
When the follicular phase begins, levels of estrogen and progesterone are low. As a result, the top layers of the thickened lining of the uterus (the endometrium) break down and are shed, and menstrual bleeding occurs.2 Around this time, the follicle-stimulating hormone level increases slightly, stimulating the development of several follicles in the ovaries, each of which contain an egg.2 Later in this phase, as the follicle-stimulating hormone level decreases, only one follicle continues to develop, producing estrogen.2
A surge in luteinizing hormone and follicle-stimulating hormone levels starts the ovulatory phase.2 Luteinizing hormone stimulates egg release, which leads to ovulation, occurring approximately 16 to 32 hours after the surge begins.2 The estrogen level peaks during the surge, and the progesterone level starts to increase.2
During the luteal phase, luteinizing hormone and follicle-stimulating hormone levels decrease.2 The ruptured follicle closes after releasing the egg and forms a corpus luteum, which produces progesterone, while estrogen levels are high.2 Progesterone and estrogen cause the lining of the uterus to thicken more, to prepare for possible fertilization.2 If the egg is not fertilized, the corpus luteum degenerates and no longer produces progesterone, the estrogen level decreases, the top layers of the endometrial lining break down and are shed, and menstrual bleeding occurs, leading to the start of a new cycle.2
Menstrual Complaints: Diagnoses and Testing for Common Causes
Menstrual disorders are one of the most common complaints in adolescent girls due in part to the difficulty in understanding what a normal cycle is, as well as menstrual cycle variabilities, which are common in this age group.3,4
As described above, a regular ovulatory cycle occurs every 21 to 35 days and last approximately up to 7 days. The average blood loss is 80 mL or less, which should require six or fewer pads being changed in a 24-hour period.3,4 In the first year after menarche, about 50% of cycles are anovulatory, but about 95% of cycles fall into the normal range by the third year after menarche.3
The key to adequate diagnoses of abnormal uterine bleeding in adolescents is history taking. Detailed questions about menstrual history should include age at menarche, timing and duration of periods, quantity of bleeding by quantifying number of fully soaked pads per day of period, and the presence of cramping and clots.4
Most abnormal uterine bleeding in this age group is likely caused by dysfunctional uterine bleeding (DUB) due to an immature hypothalamic-pituitary-ovarian axis, which causes anovulatory cycles, leading to irregular bleeding.3 However, before this diagnosis can be made it is important to rule out other, more serious conditions such as bleeding disorders, congenital anomalies, infections, and hyperandrogenism, as well as ruling out pregnancy and sexually transmitted infections even if sexual activity is not revealed or is denied.4
After a thorough history has been taken, a complete review of systems needs to be done and it should include psychosocial stressors, weight changes, eating and exercise habits, medications, and symptoms of hyperandrogenism.3,4 Obtaining a family history of bleeding disorders and the menstrual history of family members is key, as is the patient's sexual history.3,4
The physical examination should include vital signs and evaluation for signs of hyperandrogenism and bleeding.3,4 The patient's sexual maturity should be determined via Tanner staging. An internal pelvic examination is not necessary to assess anatomy, but an ultrasound can be ordered to evaluate for any pelvic pathology.3
As emphasized earlier, the laboratory testing must include a pregnancy test and sexually transmitted infection test regardless of history of sexual activity.3 A complete blood count to evaluate for anemia is important.3,5 For those with severe menstrual bleeding, an evaluation for a bleeding disorder is warranted and should include partial thromboplastin time, prothrombin time, assessment of platelet function, plasma von Willebrand factor (VWF) antigen, and plasma VWF activity via the ristocetin cofactor activity.5 Thyroid function testing should be a part of the testing because thyroid dysfunction is a common cause of abnormal uterine bleeding.5 Signs of polycystic ovarian syndrome or insulin resistance should alert a provider of the need for testing that includes free testosterone, insulin, and glucose levels, as well as evaluation of adrenal glands to look for abnormalities.3,5 Finally, headaches and nipple discharge should prompt prolactin testing.5
Management of Dysfunctional Uterine Bleeding
Management of DUB depends on the level of anemia and hemodynamic stability. For mild uterine bleeding with a patient hemoglobin level of 12 g/dL or greater, management is in the outpatient setting with observation and reassurance.1,6 The patient should keep a menstrual calendar and follow-up should occur in 3 to 6 months (or sooner if bleeding increases in severity).1,6
For patients with moderate amounts of bleeding and a hemoglobin level of 10 to 12 g/dL, hormonal therapy may be offered.1,6 These patients generally have moderately prolonged or frequent menses every 1 to 3 weeks with flow that is moderate to heavy without signs of hypovolemia or hemodynamic instability.1,6 Hormone therapy will stabilize the endometrium proliferation and shedding.1,6 Iron may also be recommended as a supplement for adolescents in this category.1,6 Oral contraceptives with combined estrogen and progestin rather than contraceptives with only progestin tend to be more effective due to the fact that estrogen provides hemostasis.6 There are a few options on how to manage these patients; these include using a monophasic contraceptive pill once daily or 3 times per day until bleeding stops (which tends to occur within 48 hours), and then tapering it to twice a day for 5 days, with a decrease to once-daily dosing to complete 21 days of therapy.6 After the 21 days of therapy, the patient should start another pack of contraceptives in the usual fashion with once-daily dosing.6 However, if bleeding recurs when the dose is decreased, it is recommended that the patient return to twice-a-day dosing for a prolonged period of time.6 Finally, close follow-up is critical during the nontypical days of taking two or three pills per day, and antiemetic therapy with agents such as ondansetron is often needed due to the higher doses of estrogen that can cause nausea and vomiting.6 Progestin-only therapy is an option for those who have an estrogen contraindication, but it tends to be less effective.6
Severe amounts of bleeding are defined as requiring changing of menstrual products every 1 to 2 hours with flow lasting longer than 7 days and loss of more than 80 mL of blood (which equates to more than 6 fully soaked pads per day).1,6 This may be associated with a bleeding disorder, and hospitalization may be necessary.6 These patients will have hemoglobin levels of less than 10 g/dL. For those with hemoglobin levels less than 6 g/dL or who have symptomatic anemia with hemodynamic instability, hospitalization is necessary.6 Those with hemoglobin levels between 8 and 10 g/dL who are hemodynamically stable and with a reliable family situation where phone contact is readily available may be managed in the outpatient setting with daily monitoring.6
Girls who are hospitalized should undergo an evaluation for a bleeding disorder as described above. Coagulation disorders have been seen in 20% of adolescents who are hospitalized with menorrhagia.5 Consultation with hematology is encouraged. Blood transfusion decisions should be individualized, and at times conjugated equine estrogen given intravenously is indicated.5
Follow-up and long-term care are essential in these patients to ensure bleeding profile has improved. Long-term management may include continuing with hormonal therapy for at least 6 months, and after discontinuation the patient should be followed to ensure her menstrual cycle continues to remain regular.5,6
Pediatricians will commonly encounter adolescent menstrual concerns in everyday practice, and understanding the normal pattern of development will ensure appropriate action on the part of the practitioner.
Most parents and their teens will only require reassurance and an explanation of what normal looks like. However, it is important to understand the warning signs that could be associated with a more serious condition requiring treatment as described.
Follow-up is key to ensure continued normal development and normalization of the menstrual cycle for the adolescent, and the use of a diary to monitor cycles closely should be encouraged.
- Emans SJ. Dysfunctional uterine bleeding. In: Emans SJ, Laufer MR, Goldstein DP, eds. Pediatric and Adolescent Gynecology. 5th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2005:227–270.
- Emans SJ. The physiology of puberty. In: Emans SJ, Laufer MR, Goldstein DP, eds. Pediatric and Adolescent Gynecology. 5th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2005:120–155.
- DeSilva NK. Abnormal uterine bleeding in the adolescent patient. Adolesc Gynecol Female Patient. 2010;35:25–28.
- ACOG Committee on Adolescent Health Care. ACOG committee Opinion No. 349, November 2006. Menstruation in girls and adolescents: using the menstrual cycle as a vital sign. Obstet Gynecol. 2006;108(5):1323–1328. doi:10.1097/00006250-200611000-00059 [CrossRef]
- Kulp JL, Mwangi CN, Loveless M. Screening for coagulation disorders in adolescents with abnormal uterine bleeding. J Pediatric Adolesc Gynecol. 2008;21(1):27–30. doi:. doi:10.1016/j.jpag.2007.04.002 [CrossRef]
- Stickland J, Gibson EJ, Levine SB. Dysfunctional uterine bleeding in adolescents. J Pediatr Adolesc Gynecol. 2006;19(1):49–51. doi:. doi:10.1016/j.jpag.2005.11.007 [CrossRef]