Cycles that are longer than 42 days, bleeding that occurs more frequently than 21 days, and bleeding that lasts more than 7 days should be considered abnormal, particularly after the first 2 years from the onset of menarche. Bleeding occurring less frequently than an internal of 90 days is abnormal, even in the first gynecologic year after menarche (51). The variability in cycle length is greater during adolescence than adulthood; thus, greater irregularity is acceptable if neither significant anemia nor hemorrhage is present. However, consideration should be given to an evaluation of possible causes of abnormal menses (particularly underlying causes of anovulation such as androgen excess syndromes or causes of oligomenorrhea such as eating disorders) for girls whose cycles are consistently outside normal ranges or whose cycles were previously regular and become irregular (60,61). Conditions that are associated with abnormal bleeding are listed in Table 14.6 and more fully discussed in Chapters 29–31.
Anovulation Anovulatory bleeding can be too frequent, prolonged, or heavy, particularly after a long interval of amenorrhea. The physiology of this phenomenon relates to a failure of the feedback mechanism in which rising estrogen levels result in a decline in follicle-stimulating hormone (FSH) with subsequent decline of estrogen levels. In anovulatory cycles, estrogen secretion continues, resulting in endometrial proliferation with subsequent unstable growth and incomplete shedding. The clinical result is irregular, prolonged, and heavy bleeding.
Studies of adolescent menses show differences in rates of ovulation based on the number of months or years postmenarche. The younger the age at menarche, the sooner regular ovulation is established. In one study, the time from menarche until 50% of the cycles were ovulatory was 1 year for girls whose menarche occurred when they were younger than 12 years of age, 3 years for girls whose menarche occurred between 12 and 12.9 years of age, and 4.5 years for girls whose menarche occurred at 13 years of age or older (62).
Pregnancy-Related Bleeding The possibility of pregnancy must be considered when an adolescent seeks treatment for abnormal bleeding (Table 14.7). Bleeding in pregnancy can be associated with a spontaneous abortion, ectopic pregnancy, or other pregnancy-related complications, such as a molar pregnancy. In the United States, 30% of 15-to 17-year-old adolescent girls have had sexual intercourse, as have 70.6% of those 18 to 19 years old (63). Issues of confidentiality for adolescent health care are critical to an adolescent’s willingness to seek appropriate reproductive health care (see Chapter 1).
Exogenous Hormones The cause of abnormal bleeding that is experienced while an individual is taking exogenous hormones usually is very different from bleeding that occurs without hormonal manipulation (64). Oral contraceptive use is associated with breakthrough bleeding, which occurs in as many as 30% to 40% of individuals during the first cycle of combination pill use. In addition, irregular bleeding can result from missed pills (65,66). Strict
Table 14.7 Causes of Bleeding by Approximate Frequency and Age Group compliance with correct and consistent pill taking is difficult for many individuals who take oral contraceptives; one study reported that only 40% of women took a pill every day (67). Other studies suggest that adolescents have an even more difficult time taking oral contraceptives than do adults, missing an average of three pills per month (68). A study of urban teens reported approximately two episodes of three or more consecutive missed pills occurring during each 3-month interval (69). With this many missed pills, it is not surprising that some individuals experience irregular bleeding. The solution is to emphasize consistent pill taking; if the individual is unable to comply with daily pill use, an alternative contraceptive method may be preferable.