Case presentation
We present a term baby girl born to a 35-year old Caucasian woman in her
first pregnancy with an uneventful medical history. Informed consent was
obtained prior to publication.
Dating (12 weeks of gestation) and anomaly (20 weeks of gestation) scans
were reported as normal. A growth scan was requested at 35 weeks 6 days
of gestation due to a low maternal BMI of 17.84 kg/m2.
Normal fetal movements were reported and there were no maternal concerns
at the time of this scan.
The growth scan revealed that although the umbilical artery Doppler was
normal, the estimated fetal weight was below the fifth centile. The
liquor volume was adequate with a maximum pool depth of 7 cm and
satisfactory fetal movements were seen. A well-rounded mass containing
low level echoes was identified in the fetal pelvis superior and
posterior to the urinary bladder. The fetal urinary bladder, kidneys and
the stomach were demonstrated and appeared normal. No obvious mass
pressure effect was seen in the fetal abdomen.
As per hospital protocol, the woman was referred to the Fetal Medicine
Department for a further scan which identified a 3.5 x 3.7 x 8 cm solid
mass in the abdomen behind the bladder and in the midline, most likely
representing an enlarged uterus in this female fetus. The external
genitalia, renal tract and bladder appeared normal. The scan confirmed
that the fetus was small for gestational age. No other structural
abnormalities were seen within limits of late gestational age and a
probable diagnosis of a fetal hematometrocolpos was made (Figure 1A).
The woman was counselled about the findings, and a plan was made for
baby to have a postnatal abdominal ultrasound scan to confirm the
diagnosis and to be transferred to the surgical centre at the
[blinded] Hospital for intervention. Since these findings are
usually not associated with underlying chromosomal or genetic problems,
amniocentesis was not offered. Increased surveillance was arranged
because of the growth restriction with serial growth scans.
The baby was born in good condition vaginally by forceps assisted
delivery following induction of labor at 39 weeks of gestation with a
birth weight of 2625 grams. On physical examination, a protruding
vaginal mass was noted, with no signs of ulceration or infection. Both
femoral pulses were felt with difficulty, but there was good distal
perfusion to both legs. The rest of the physical examination was
unremarkable. Baby was passing urine and opening her bowels normally.
Her renal function parameters were normal.
An ultrasound of the baby’s abdomen and pelvis was performed on the day
of birth confirming a thin walled cystic structure filling the pelvis
and extending up to the umbilicus and bilaterally into both adnexae
(Figure 1B). The structure measured 7.3 x 3.1 x 6 cm and contained
echogenic fluid. There was no internal vascularity demonstrated. At the
superior border of the structure, a lobulated, more solid looking focus
measuring 16 x 8 x 13 mm with elements of shadowing was described,
suggested to be possible calcification, also with no internal
vascularity. It was not possible to identify a vagina. The liver, spleen
and kidneys had normal appearances and there was no hydronephrosis. The
urinary bladder was virtually empty and only seen low in the pelvis and
anterior to the cystic mass. The femoral vessels were patent. Overall,
appearances were suggestive of a hematometrocolpos with a possible small
clot at the fundal aspect.
The baby was transferred to the [blinded] Hospital and had surgery
under general anesthesia on the third day of life which involved
incision of the imperforate hymen and drainage of the hematometrocolpos,
followed by a cystovaginoscopy which was normal. She was discharged home
the following day. A repeat abdominal ultrasound scan was performed at
three months of age, showing no recurrence (Figure 1C). The pre-pubertal
uterus was normal with no fluid seen, as were the ovaries and bladder.