Pediatric emergency medicine trisk 388

Additional emphasis should be placed on the abdominal examination—palpating
for a uterine fundus, suprapubic and/or lower quadrant tenderness. Particular
attention should be placed on pelvic examination, which consists of visualizing
the external genitalia, performing the bimanual examination, and using a
speculum to visualize the vaginal vault and cervix. Visualization of the external
genitalia allows the clinician to verify the origin of the bleeding, assign Tanner
pubertal staging, and assess for signs of virilization, trauma, or discharge. For
adolescents with more significant blood loss, anemia, or concerns for sexually
transmitted infection, the examination then includes a bimanual examination to
assess for the presence of a vaginal foreign body or mass and to determine
cervical motion, uterine, and/or adnexal tenderness. The speculum examination
may be reserved for girls who have significant, ongoing blood loss as this
procedure is perceived as relatively invasive by many teens. NAAT testing on
urine has become the standard thus collecting swabs is usually not necessary.

FIGURE 79.3 Diagnostic approach to abnormal uterine bleeding after menarche—nonpregnant
patients.

Universal pregnancy testing is recommended for all adolescent girls presenting
with abnormal bleeding. Often teens do not feel comfortable disclosing their
sexual history. Uterine bleeding in the pregnant patient is an obstetric emergency.
A complete blood count (CBC) with differential is also recommended for teens
presenting with heavy bleeding because estimates of blood loss based on pad or


tampon use are typically inaccurate. Given the prevalence of sexually transmitted
infection in this age group, screening for Chlamydia trachomatis and N.
gonorrhoeae via nucleic acid amplification testing of the urine or vaginal swab is
recommended. Further evaluation for bleeding disorders and/or endocrine causes
is indicated based on clinical suspicion. Coagulation studies such as prothrombin
time (PT)/thromboplastin time (PTT), fibrinogen, von Willebrand assay (includes

von Willebrand factor antigen, ristocetin cofactor assay, and factor VIII), and
bleeding time may be helpful in patients with heavy cyclical bleeding from
menarche and those with more severe degree of anemia (hemoglobin less than 10
mg/dL). Von Willebrand studies, however, may be misleadingly normal during
acute bleeding or in the presence of estrogen. Endocrine studies may be
considered including TSH, prolactin, dehydroepiandrosterone sulfate (DHEAS),
testosterone profile, androstenedione, and 17-hydroxyprogesterone. Consultation
with adolescent, hematology, and endocrine specialists can be considered as
clinically indicated.

Causes of Uterine Bleeding in the Adolescent Patient
The differential diagnosis of abnormal genital bleeding is broad, and one must
consider all the diagnostic possibilities during the evaluation. For the vast
majority of adolescents evaluated in the ED for excessive bleeding, the most
common causes are anovulation, usually related to immaturity of the
hypothalamic–pituitary–gonadal axis or polycystic ovarian syndrome, and
sexually transmitted infection. It is crucial to evaluate for pregnancy-related
conditions early in all postpubertal girls with bleeding, even if sexual activity is
denied. Vaginal bleeding may be the result of accidental injury or trauma from
either a consensual or abusive relationship. A foreign body such as a retained
tampon or an intrauterine device may cause abnormal bleeding. Rare causes
include hematologic disorders, thyroid or adrenal disease, prolactinomas, or
another central nervous system neoplasm. Structural abnormalities of the
reproductive tract such as uterine fibroids or polyps are highly unusual causes in
the adolescent age group (see Table 79.2 ).


TABLE 79.2
DIFFERENTIAL DIAGNOSIS OF ADOLESCENT ABNORMAL
UTERINE BLEEDING

Anovulation
Hypothalamic–pituitary–gonadal axis immaturity
Polycystic ovarian disease
Hormonal contraceptives
Pregnancy
Threatened, spontaneous, or missed abortion
Placenta previa, placenta accretia
Ectopic pregnancy
Infection
Cervicitis (especially chlamydial)
Pelvic inflammatory disease
Trauma
Laceration
Sexual abuse
Foreign body
Hematologic
Von Willebrand disease, platelet dysfunction
Thrombocytopenia
Coagulation defects, factor deficiencies
Endocrine
Polycystic ovarian syndrome
Thyroid disorders
Adrenal disorders
Hyperprolactinemia
Endocrine
Endocrinologic phenomena—whether physiologic, pharmacologic, or pathologic
—are the most common causes of AUB in nonpregnant adolescents. During
physiologically normal menstrual cycles, the occasional adolescent has spotty
bleeding for 24 hours or less in association with the transient decline in estrogen
level that occurs at midcycle. The unilateral pain of mittelschmerz can

accompany this brief bleeding episode.


Hormonal contraception is a common, pharmacologic cause of irregular
menstrual bleeding. Of women who use birth control pills containing 35 μg or
less of estrogen, 5% to 10% will have breakthrough intermenstrual spotting or
bleeding, especially during the first 3 months of contraceptive pill use.
Breakthrough bleeding is also a common side effect of progestin-only
contraceptive pills, injectable medroxyprogesterone, and long-acting progestin
implants. Many patients using birth control pills experience estrogen and
progesterone withdrawal bleeding if they forget to take one or several pills.
Physiologic anovulatory cycles are frequent, especially in the first 2 years after
menarche, stemming from immaturity of the hypothalamic–pituitary–ovarian
axis. The physiology of anovulatory cycles deserves special mention as it is one
of the most common causes of irregular bleeding in adolescents. In the absence of
ovulation, the corpus luteum never forms, and estrogen continues to act on the
endometrium unopposed by progesterone. The lining becomes increasingly
thicker and eventually outgrows the supporting capabilities of the stroma.
Punctate areas of endometrial shedding give way to more significant bleeding as
the deeper layers are affected and the spiral arterioles are exposed. The treatment
of AUB from physiologic anovulation requires the administration of both
exogenous estrogen and progesterone—estrogen to stimulate endometrial
regrowth in the excessively thin areas and progesterone to strengthen the stromal
support.
Anovulatory cycles caused by polycystic ovarian syndrome should also be
considered in a teenager with AUB. Menstrual cycles may be infrequent and
irregular, as androgenic excess contributes to abnormal ovarian function and
anovulation. Polycystic ovarian syndrome is common among adolescents and
should be considered in adolescents with abnormal bleeding and stigmata of
androgen excess (hirsutism, acne, obesity).

Hypothyroidism should be considered if the patient has other symptoms or
signs of thyroid dysfunction. A functioning ovarian cyst is a less common cause
of vaginal bleeding but should be considered especially in the teenager with AUB
and an adnexal mass or tenderness.
Infection
In the nonpregnant patient with AUB, infectious causes such as cervicitis or
pelvic inflammatory disease should be considered, especially if there is pelvic
pain or tenderness. Abnormal bleeding occurs in nearly one-third of patients with
pelvic inflammatory disease, generally as a result of endometritis. Sexually
transmitted infections and pelvic inflammatory disease are discussed in detail in