Urorectal Septal Malformation Sequence: A Fetal Autopsy-Based Case Series Highlighting Phenotypic Spectrum and Associated Anomalies

Abstract Urorectal septal malformation sequence (URSMS) is a rare and complex congenital anomaly resulting from failure of the urorectal septum to appropriately divide the cloaca during early embryonic development, leading to varying degrees of urogenital and anorectal malformations. This descriptive case series presents five patients diagnosed with URSMS, including three with partial and two with complete forms, managed at a tertiary care center in South India over a 4-year period. Patients with partial URSMS exhibited features such as ambiguous genitalia, anorectal malformations with fistulous tracts, and relatively less severe genitourinary anomalies, while those with complete URSMS presented with absent perineal openings, a persistent cloaca, and more complex multisystem involvement. Comprehensive diagnostic workup, including prenatal imaging, postnatal radiology, and endoscopic evaluation, was critical for early diagnosis and surgical planning. This case series highlights the phenotypic variability of URSMS and underscores the importance of early recognition and a coordinated multidisciplinary approach to optimize patient care.