Pediatric emergency medicine trisk 1007 1007

A. Pseudocyesis
B. Stress
Early pregnancy can be challenging to recognize. Symptoms of fatigue, nausea,
vomiting (not necessarily in the morning), urinary frequency, and breast growth
or tenderness are common but by no means universal or specific. Some patients
may report the result of a home pregnancy test. However, because of variability in
the test’s sensitivity for detecting urinary human chorionic gonadotropin (hCG),
home pregnancy test kits taken in early gestation can give a false negative result.
False-positive results can also occur, though rarely. Accordingly, the emergency
physician should not rely solely on the reported result of a home pregnancy test to
make or to exclude the diagnosis of pregnancy.
Qualitative urine and serum pregnancy tests performed in medical settings
generally detect the β-subunit of hCG (β-hCG). The urine pregnancy test
threshold is generally at β-hCG levels of ≥20 mIU per mL and will permit the
detection of a normal pregnancy within about 10 days after conception and, in
most by the time an expected menstrual period is missed. Serum β-hCG can be
detected at lower levels though laboratories are variable regarding the level of
detection (<1 vs. <5 mIU per mL). The emergency physician should know the
detection level of the quantitative and qualitative β-hCG tests used by their
laboratory. Ectopic pregnancies often produce abnormally low levels of β-hCG
compared to an intrauterine pregnancy of the same gestational age (see Chapter
79 Vaginal Bleeding ). If a patient with one or several missed menstrual periods
also complains of abdominal pain or abnormal vaginal bleeding, the diagnosis of
ectopic pregnancy must be considered (see Chapters 92 Gynecology Emergencies
and 119 Genitourinary Emergencies ). Although more than half of women with
ectopic pregnancy have no risk factors, prior infections with chlamydia,
gonarrhea, or pelvic inflammatory disease all increase the likelihood that a
subsequent pregnancy will be ectopic.

Evaluation of Nonpregnant Patients
After pregnancy is excluded, the evaluation of an adolescent with oligomenorrhea

can proceed at a deliberate pace ( Fig. 51.1 ). During the first 2 years after
menarche, it is not unusual for girls to have an occasional menstrual cycle that
lasts less than 25 days or more than 40 days. After 3 years of menstruating, the
typical menstrual cycle lasts 21 to 34 days for a majority of girls. As a rule, if an
adolescent who is within 2 years of menarche complains of only one or two
prolonged menstrual cycles and is not sexually active, further investigation in the