# Isolated Fetal Ascites Secondary to Persistent Urogenital Sinus

Authors: D. Camanni; A. Zaccara; M. L. Capitanucci; G. Mosiello; I. Capolupo; B. D. Iacobelli; M. De Gennaro
Journal: Obstetrics and Gynecology International
 (2009)

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## Abstract

Objective. To present a case of isolated ascites secondary due to urogenital abnormalities (urogenital sinus) without any other prenatal ultrasound marker. Method. A 36-year-old woman with prenatal isolated ascites delivered a female baby, weighing 2.285 g; ascites was drained at birth and the baby underwent several episodes of urinary retention prior to undergoing X-ray investigations. Results. A voiding cystourethrogram revealed a short urogenital sinus: a vesicostomy was performed. A vaginoscopy revealed double vagina with a large posterior vagina. A posterior sagittal anorectal pull-through with genitoplasty was performed at 2 years old with 1-year follow-up. Conclusions. Though rare, a urogenital abnormality is to be suspected in fetal ascites cases with negative viral tests and no cardiac anomalies. The most common ultrasound marker of such abnormalities (fluid filled cavity) may be missing because of complete drainage of urine through the tubes into peritoneum.


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## Body

## 1. Introduction

Persistent
urogenital sinus (UGS) is a rare congenital anomaly in which failure of
urethrovaginal separation results in one orifice for bladder and vagina to
drain through.These
patients exhibit a great internal and external anatomical variability, which
may lead to aberrant drainage of urine because of the confluence of the two
systems. In recent years, prenatal diagnosis has enabled identification of this
condition early in gestation. The commonest ultrasound finding is the presence
of a cystic pelvic structure with or without septa, which represents a
fluid-filled vagina and which may compress urinary tract (hydrometrocolpos)
[1].Occasionally,
some cases may also present with prenatally detected urinary ascites due to
urinary reflux through the genital system into peritoneum. We herein report the
case of persistent UGS in which prenatal ascites was the only ultrasonographic
finding.


## 2. Case Report

A 36-year-old woman, gravida 3, para 2, was presented at 22-week gestation with ultrasonographic
evidence of fetal ascites. Amniotic fluid was normal and TORCH serology was
negative. Fetal anatomy was unremarkable with the exception of a moderately
distended bladder (Figures1(a), 1(b)). Amniocentesis for karyotyping showed 46, XX
and ascites was confirmed at 31-week
gestation with significant elevation of diaphragm, prompting elective
caesarean section.(a) Prenatal ultrasound of the fetus with significant ascites.
(b) Moderately distended bladder is visible in a pelvic scan.
(a)(b)A 2.285 g female newborn was delivered. A physical
examination revealed a massively distended abdomen with normal looking external
genitalia. Four hundred millilitres of clear ascitic fluid were drained from
abdominal cavity with immediate improving of respiratory status. Fluid analysis
revealed some nucleated cells with normal protein concentration. On day 2 of
life, a distended bladder became evident;  Foley catheter was positioned without
difficulty, which drained normal urine. Renal ultrasound did not show any
urinary tract dilatation. Over the following days, an incremental diuresis was
observed with no ascites reaccumulation.After removal of bladder catheter, bladder distended
again and the catheter had to be reinserted. A voiding cystogram was then
performed which demonstrated a short (1.5 cm) UGS with the catheter at the junction
between bladder and vagina (Figure2). UGS was confirmed at cystoscopy and
vesicostomy was carried out since baby was persistently unable to void. At
vaginoscopy, a duplicated vagina draining into sinus was found. At 2 years, the
baby underwent urogenital reconstruction
with total urogenital mobilization. At 2-year follow-up, the patient has
complete day-time urinary continence with some residual wet episodes in the
night.Voiding cystogram showing UGS
with Foley catheter at the confluence of bladder and vagina.
(a)(b)(c)


## 3. Discussion

Persistent UGS is considered secondary to failure of normal descent of the urogenital
septum, leaving confluence of vagina and urethra proximal to the introitus.
Such condition is most commonly associated to adrenogenital syndrome with
various degrees of virilisation [2] but it may also occur in normal appearing
external genitalia, as it was in our patient.As previously mentioned, distended vagina with
hydrometrocolpos was the most common antenatal finding [3]. As Adams et al.  pointed out [4], this may be due to
significant outflow resistance to urine through the common channel which may
impede good emptying of urine. Hydrometrocolpos may be the result of backflow
into the vagina during micturition [5]. Ascites, in turn, can be secondary to urine
reflux of urine through fallopian tubes. In an extensive review of nonimmune fetal ascites, Favre et al. reported
ascites of urinary origin in 15 cases. Posterior urethral valves were diagnosed
in 14 cases and ureterocele in one. All cases presented with remarkable
dilatation of urinary tract [6]. These authors also reported prenatal ascites
in 8 cases of cloacal dysgenesis; however, this was never an isolated finding.In 2008, Puhl et al. described fetal urogenital
sinus with associated urogenital defects (bilateral hydronephrosis). Ascites was
moderate [7], the same findings were confirmed by Gul et al. who reported association
of UGS, ureterocele, hydroureter, and hydronephrosis [8].Our patient was at significant variance with
previously reported cases in that isolated ascites was the only documented
finding throughout pregnancy.Therefore, attention was primarily directed to common
causes of isolated ascites such as viral infections or cardiovascular problems
[9, 10]. As previously mentioned, TORCH serology and all other examinations
were normal both antenatally and immediately after birth. However, because of
significant elevation of diaphragm, ascites had to be drained before
establishing diagnosis. It was not until the second day of life when poor
bladder drainage demanded catheterization, that a urogenital problem was
suspected.We do not have an explanation for the absence of any
vaginal distention at prenatal ultrasound. We might speculate that a free flow
of urine was present at uterovaginal junction preventing fluid accumulation;
however, we have not been able to confirm such hypothesis intraoperatively
neither there is any study in Literature describing anatomical features of uterovaginal
junction in patients with UGS or cloacal anomalies.Moreover, in
our patient, the UGS was only 1.5 cm in length and this makes interpretation of
prenatal ultrasound findings even more difficult. As a matter of fact, intraperitoneal reflux of
urine in UGS patients was observed only in long, narrow sinuses with high
confluence or vagina [11].


## 4. Conclusions

Our findings suggest that prenatal diagnosis of
persistent UGS should be suspected not only in cases of documented hydrocolpos
but also in cases of isolated ascites. The underlying mechanism of such
accumulation may be secondary to reflux of urine into peritoneum. Viral tests
and screening for cardiac abnormalities should continue to be first line
examinations; however, in case of negative tests and unremarkable fetal
anatomy, the suspicion of urogenital anomalies should be incorporated into
prenatal counselling with appropriate information about such conditions being
conveyed to the prospective parents.



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*Source: 219010-2009-02-15.xml*