Pediatric emergency medicine trisk 2162 2162

Vaginal outlet anomalies should be considered in infants presenting
with an abdominal mass or in adolescents with abdominal pain,
particularly if the patient has normal pubertal development without the
onset of expected menarche.
Vaginal outlet obstruction can cause acute urinary retention in any age
female.
A complete physical examination can easily diagnose imperforate
hymen.

CONGENITAL VAGINAL OBSTRUCTION
An obstructed vagina will eventually accumulate fluid, causing distention and,
eventually, symptoms. Anatomic vaginal obstructions present most often during
adolescence, when menstrual blood fills the vagina, producing hematocolpos or
hematometrocolpos. There are multiple case reports of vaginal obstruction
presenting in the neonatal period (incidence of approximately 0.006%), when
vaginal distention is caused by mucus secreted as a result of stimulation by
maternal hormones, a condition called hydrometrocolpos.
The two most common anomalies that lead to vaginal outlet obstruction are
imperforate hymen (approximately 0.1% of term female neonates) and transverse
vaginal septum (sometimes called vaginal atresia; 1 in 30,000 to 84,000 women).
These malformations are probably produced between the 16th and 20th weeks’
gestation if the developing vaginal plate fails to perforate at its junction with
either the fused paramesonephric (müllerian) ducts proximally or the urogenital
sinus caudally. Unlike patients with a transverse vaginal septum or imperforate
hymen, patients with complete agenesis of the vagina (Rokitansky–Küster–
Hauser syndrome) have rudimentary uteri or none at all, so hydrocolpos does not
occur.
Although vaginal obstruction should be properly identified during the initial
examination of the newborn female, infants with hydrocolpos often go
unrecognized until days or weeks later when they develop the three hallmarks of
this condition: (i) a lower abdominal mass, (ii) difficulty with urination, and (iii) a

visible bulging membrane at the introitus. In more severe cases, infants may also
have constipation, hydronephrosis, edema of the lower extremities, and
hypoventilation. A complete physical examination should immediately indicate
the proper diagnosis. In adolescence, a female with congenital vaginal obstruction
will usually present with primary amenorrhea and/or lower abdominal pain with
associated hematocolpos; this condition should be suspected in patients with