The adolescent’s experience and expression of illness and pain should be viewed within the context of her life experiences. Most adolescents have limited life experiences with problems such as pain, discomfort, or bleeding. An adolescent may state that she is experiencing the “worst pain of her life” and yet may appear to be reasonably comfortable. She may well be stating the truth about this experience, which the clinician must still interpret differently from the symptoms of an adult woman who, for instance, may be in active labor. It should be remembered that an individual’s response to illness and pain is to some extent a learned behavior.
To assess vaginal bleeding during adolescence, it is necessary to understand the range of normal menstrual cycles (see Chapter 7). During the first 2 to 5 years after menarche, most cycles are anovulatory. Despite this, they are somewhat regular, within a range of approximately 21 to 45 days, in contrast to adult women, whose cycles typically range between 21 and 38 days (51–55). In more than one-fourth of girls, a pattern of plus or minus 10 days and a cycle length of 21 to approximately 45 days are established within the first three cycles; in one-half of girls, the pattern is established by the seventh cycle; and in two-thirds of girls, such a pattern is established within 2 years of menarche (53) (Table 14.5).
The mean duration of menses is 4.7 days; 89% of cycles last 7 days. The average blood loss per cycle is 35 mL, and the major component of menstrual discharge is endometrial tissue (56). An 80 mL/cycle is used as a definition of heavy menstrual bleeding and recurrent bleeding in excess of 80 mL/cycle results in anemia, although the clinical utility of the 80 mL/cycle is questioned (57,58).
The common clinical practice of asking how many pads or tampons are soaked on a heavy day or per cycle can give a rough approximation of blood loss (three to five pads per day is typical). Individual variations in fastidiousness, lack of familiarity with the volume of blood loss other than one’s own, and errors in estimation or recollection result in inaccuracies in estimations of menstrual volume. One study found that one-third of individuals who estimated their cycles to be moderate or light had bleeding in excess of 80 mL/cycle, whereas nearly one-half of those who described the bleeding as heavy had ﬂow less than 80 mL/cycle (59). In addition, the amount of menstrual blood contained in each tampon or pad may vary both within brands as well as from one brand to another (57). However, changing a pad hourly, clots larger than “50 pence size,” and requiring a change overnight are associated with a measured volume of greater than 80 mL (58).
The transition from anovulatory to ovulatory cycles during adolescence takes place during the first several years after menarche. It results from the so-called maturation of the hypothalamic–pituitary–ovarian axis, characterized by positive feedback mechanisms in which a rising estrogen level triggers a surge of luteinizing hormone and ovulation. Most adolescents have ovulatory cycles by the end of their second year of menstruation, although most cycles (even anovulatory ones) remain within a rather narrow range of approximately 21 to 42 days.
Table 14.5 Parameters for Normal Menstrual Cycles in Adolescents
From Hillard PJ. Menstruation in young girls: a clinical perspective. Obstet Gynecol 2002;99:655–662.
Table 14.6 Conditions Associated with Anovulation and Abnormal Bleeding
Androgen excess syndromes (e.g., polycystic ovary syndrome [PCOS])
Differential Diagnosis of Adolescent Abnormal Bleeding