++
Close to 800,000 adolescents between 15 and 19 years old in the
United States experience a pregnancy each year, with approximately
30% of these pregnancies terminated by therapeutic abortion,
14% resulting in spontaneous abortion, and the balance
resulting in a live birth. Although these data reflect a significant
issue impacting adolescent health and well-being, trends in pregnancy,
abortion, and birth among US adolescents continues on a downward
trend over the past 25 years.1 Of those who maintain
the pregnancy to term, about 95% of adolescents decide
to parent the child, and 79% of teen mothers are unmarried.2 The factors
that place young women at risk for an unintended pregnancy and the
interactions among these factors are complex. Lack of appropriate
knowledge regarding sexual intercourse and contraception plays a
role in the perpetuation of myths regarding risk for pregnancy,
especially among younger teenagers. Cognitive immaturity results
in adolescents’ difficulty in linking the act of sexual
intercourse with the possible outcome of pregnancy and therefore
assessing their true personal risk for pregnancy as well as difficulty
in applying information that they may have to their own decision-making
related to sexual behavior and pregnancy prevention. Environmental
factors including poverty, community norms, and cultural expectations
make teenage parenthood an attractive alternative role for many
young women. Also, society’s ambivalence regarding adolescent
sexual activity, contraception, pregnancy, and teenage parenthood acts
as a barrier to the development and maintenance of effective interventions.
++
During any assessment of a female adolescent, it is advisable
to record the date and normality of the last menstrual period. A
history of unprotected intercourse since the last menses with or
without amenorrhea or unusual vaginal bleeding should alert the
physician to the possibility of pregnancy. The absence of historical
information does not preclude pregnancy because often the adolescent
is unwilling to communicate sexual information to the clinician.
In addition to amenorrhea or a “missed period,” the
typical symptoms associated with pregnancy (nausea, vomiting, intermenstrual
spotting, breast tenderness, unexplained weight gain, urinary frequency, and
fatigue, among others) may be present in any combination or may
be absent early in pregnancy.
+++
Evaluation for Pregnancy
++
A physical assessment, including a pelvic examination, is critical
to the evaluation of a possible pregnancy. The pregnancy test confirms
the presence of an early pregnancy, using detection of β-human
chorionic gonadotropin (β-HCG) in the urine. Within
24 hours of implantation, the placenta initiates production of HCG
(⩽ 5 mIU/mL), and concentrations double every 48 to 72
hours in a normal pregnancy. By 2 weeks, the level rises to more
than 200 mIU/mL in a normal pregnancy, and concentration
peaks at approximately 100,000 mIU/mL at 6 to 8 weeks. Thereafter,
the level drops to below 10,000 mIU/mL by 14 weeks. Currently,
urine testing using monoclonal antibodies to β-HCG
provides an accurate, sensitive, easy, and inexpensive screening
tool to detect early pregnancy with sensitivities to levels of 5
to 50 mIU/mL. Thus, testing performed ...