Prenatal ultrasonographic and magnetic resonance imaging findings of congenital cloacal anomalies associated with meconium peritonitis

Background/PurposeCloacal malformations are rare anomalies, occurring in females, and in which they demonstrate a single perineal orifice for urethra, vagina, and rectum. Prenatal ultrasonograms (US) of cloacal malformations sometimes show ascites, hydrocolpos, and hydronephrosis. We herein describe the characteristic prenatal US and magnetic resonance imaging (MRI) findings of the cloacal malformations associated with meconium peritonitis.MethodsThe pre- and postnatal records of 11 newborn patients with cloacal malformations, treated in our hospital from 1988 to 2004, were reviewed. All fetuses underwent prenatal US by experienced obstetricians, whereas in addition, fetal MRI was performed in 1 patient.ResultsThe prenatal US and/or MRI findings showed fetal ascites, a multicystic pelvic mass, oligohydramnios, and bilateral hydronephrosis in 5 of 11 patients with cloacal malformations. In these 5 cases, postnatal examinations showed associated hydrocolpos, hydrometrocolpos, and bilateral hydronephrosis; furthermore, 4 of these 5 cases also showed meconium peritonitis at laparotomy.ConclusionsThe prenatal US and MRI findings, showing fetal ascites, multicystic pelvic mass, bilateral hydronephrosis, and oligohydraminios are highly suggestive of the cloacal malformations associated with meconium peritonitis.