Prenatal diagnosis of cloacal malformations

Prenatal diagnosis of anorectal malformations currently occurs in 0-15.9% of screened cases. In cloacas, these numbers are unknown. We speculate that some images from prenatal ultrasound studies may suggest the diagnosis of cloaca, but are not recognized because of a lack of suspicion for this diagnosis.

A retrospective review of the medical records of 489 patients born with cloaca was performed; 95 of them had prenatal ultrasound reports that represent the material analyzed for this study. A literature review was performed, finding 31 publications, with 68 cloaca patients detected by prenatal images. The abnormal findings of our patients were compared with those described in the literature to determine the most common abnormal prenatal images found in patients with cloaca.

The 95 ultrasound reports found in our patients described 270 abnormalities, the most frequent were: abdominal/pelvic cystic/mass (39), hydronephrosis (36), oligohydramnios (23), distended bowel/bowel obstruction (19), ascites (15), 2 vessel cord (14), dilated bladder (14), dilated ureter (14), polyhydramnios (10), echogenic bowel (8), multicystic kidney (8), "ambiguous genitalia" (7), hydrops fetalis (7), hydrocolpos (4), absent kidney (3), abnormal spine (3), and anorectal atresia (3). In spite of these findings, the radiologists who interpreted the studies only suspected a cloaca in 6 cases (6%). The literature review showed 212 abnormalities in 68 demonstrated cloaca patients. The most frequent were: abdominal/pelvic cystic/mass (46), hydronephrosis (44), ascites (21), oligohydramnios (20), distended bowel (11), multicystic dysplastic kidney (7), ambiguous genitalia (6), non-visualization of the bladder (6), two-vessel cord (5), dilated bladder (5), intraabdominal calcification (4), polyhydramnios (4), enterolithiasis (4), hydrometrocolpos (3), and dilated ureter (3).

We conclude that it is possible to suspect the diagnosis of cloaca, prenatally, more frequently than what currently occurs, looking at the same images but with an increased index of suspicion for cystic abdominal masses and a combination of gastrointestinal and urological abnormalities.