The attainment of ovulatory menstrual cycles is one feature of
maturation and synchronization of the hypothalamic-pituitary-gonadal
axis. Despite frequent anovulatory cycles, the majority of menstrual
cycles during adolescence range from 21 to 42 days with duration
of menstrual flow lasting 2 to 8 days. Young women frequently complain
of menstrual abnormality when their cycle falls within the expected
range of normal. Charting cycles on a calendar is a useful tool
to evaluate cycle irregularity.1 The most common
menstrual disorders in adolescents, including amenorrhea, dysfunctional uterine
bleeding, and dysmenorrhea, are discussed in this section.
Amenorrhea is traditionally divided into 2 categories: primary
and secondary. Primary amenorrhea is defined as either (1) the failure
to menstruate by age 16 (age of expected menarche) in the presence
of breast development and normal growth or (2) delayed menarche
by 14 years of age in the absence of secondary sexual characteristics.
Despite evidence that puberty may be occurring earlier, no revision
to the definition of delayed puberty and primary amenorrhea is uniformly endorsed.
When significant delay in secondary sexual development and accompanying
amenorrhea is detected, prompt evaluation rather than waiting for
an adolescent to meet strict criteria should occur.2,3
Secondary amenorrhea is defined as either (1) cessation of menses
for more than 3 cycle intervals or 6 consecutive months in females with
previous regular menses or (2) cessation of menses for more than
12 months in females with previous irregular menses.1,2 The
categorization of primary and secondary amenorrhea is retained;
however, the clinical approach to primary and secondary amenorrhea
in the female adolescent and young adult is similar. All causes
of secondary amenorrhea may also present as primary amenorrhea.
Oligomenorrhea, or infrequent menses, is considered as amenorrhea
in this discussion. Amenorrhea is further discussed with delayed
puberty in Chapter 541.
Pregnancy is the most common cause of secondary amenorrhea and
must not be overlooked as a potential cause of primary amenorrhea.
The diagnosis of pregnancy is reviewed in Chapter 77.
Beyond pregnancy, the etiology of primary and secondary amenorrhea
falls into 3 categories depending on the function of the pituitary gland
in relation to the ovary: hypogonadotropic gonadism, hypergonadotropic
hypogonadism, and eugonadotropic eugonadism.2,3
Hypogonadotropic hypogonadism indicates inadequate hypothalamic-pituitary
stimulation of the ovary and is characterized by low levels of follicle-stimulating
hormone (FSH), luteinizing hormone (LH), and estrogen.2 Hypothalamic amenorrhea
results from partial or complete inhibition of gonadotropin-releasing
hormone (GnRH) release. It may be associated with constitutional
delay of puberty; nutritional deficiencies secondary to chronic
diseases such as regional enteritis, cystic fibrosis, and poorly controlled
diabetes; anorexia nervosa; excessive exercise and accompanying
alterations in body fat and weight as found in the female athlete triad
(disordered eating, amenorrhea, osteoporosis); stress; isolated
GnRH deficiency; endocrinopathies such as hypothyroidism, congenital
adrenal hyperplasia, and Cushing disease; ...