Prenatal Diagnosis of Bladder Exstrophy and OEIS over 20 Years

Optimizing prenatal diagnosis and referral of classic bladder exstrophy: Lessons from a single-institution experience

INTRODUCTION

Classic bladder exstrophy (CBE) is a malformation of the genitourinary system that occurs due to failure of abdominal wall closure. Unlike other malformations of similar incidence, prenatal diagnosis of CBE relies on suggested, rather than formal, diagnostic criteria.

OBJECTIVE

This report describes prenatal diagnosis of CBE in the largest single-institutional cohort to date and delineates key sonographic findings and protocols for specialist referral.

MATERIALS AND METHODS

A single-institutional database was reviewed for CBE patients born since 2000. Data on screening ultrasound use, gestational age at ultrasound, and abnormal findings were extracted. Where possible, time of prenatal diagnosis (pre- or postnatal and gestational age), ultrasound findings and other imaging data, specialist referral, institution of birth and closure, and outcome of primary closure attempt were compared.

RESULTS

Of 557 patients born with CBE between 2000 and 2022, 284 met inclusion criteria and complete data were available for 280 (229 born domestically and 51 born internationally) who were included for analysis. Abnormal sonography suggestive of CBE was present for 48% (n = 134) of patients, for whom absent bladder was the most common abnormal finding (76% [102/134]). Of domestic patients, 46% (n = 106) were diagnosed prenatally at a median gestational age of 22 weeks (inter-quartile range [IQR]: 20-24), and 14% (n = 32) underwent confirmatory fetal magnetic resonance imaging. Of domestic patients with abnormal prenatal findings, 75% (n = 80/106) consulted with maternal-fetal medicine and 58% (n = 62/106) consulted with pediatric urology. On univariate analysis, prenatal diagnosis was positively associated with primary repair at Association for the Bladder Exstrophy Community-recognized centers of excellence (54% vs. 38%, p = 0.02) and negatively associated with osteotomy at primary closure (41% vs 59%, p = 0.003) but not success of primary closure (74% vs. 82%, p = 0.07).

DISCUSSION

Rates of prenatal diagnosis in this cohort were similar to previous reports of smaller cohorts. Diagnosis allows for comprehensive pre- and postnatal follow-up with a pediatric urologist, with implications on birth planning and decisions on termination of pregnancy. Because of the previously-reported association between exstrophy and in vitro fertilization, these pregnancies should undergo detailed sonography. Any nonvisualization of the fetal bladder should prompt a detailed exam, and any finding characteristic of bladder exstrophy warrants referral to pediatric urology.

CONCLUSIONS

Although CBE is a rare disorder, it is underdiagnosed during pregnancy. Sonographers and obstetricians should be aware of characteristic findings and best practices following diagnosis. Early referral to pediatric urology and maternal-fetal medicine is important for counseling and postnatal planning.

Bladder exstrophy-epispadias-cloacal exstrophy complex: characteristics, aetiologies, and epidemiologic findings

Bladder exstrophy-epispadias-cloacal exstrophy complex (BEEC) is a spectrum of congenital urologic anomalies that involve the bladder, urethra, genitalia, and pelvic musculoskeletal system, and can affect urinary continence, sexual health, and fertility. BEEC includes a wide spectrum of anatomical abnormalities with different levels of severity: epispadias represents the mildest phenotype, classic bladder exstrophy (CBE) is the most common defect, and cloacal exstrophy (CE) - often referred to as omphalocele, exstrophy, imperforate anus, and spinal defects (OEIS) complex - is the most severe form. BEEC disorders cause significant health problems and affect the health-related quality of life (QoL) of affected individuals. There have been significant insights into the aetiology of BEEC in the last decade. Specifically, recent genetic studies have suggested that downstream regulator(s) of p63, Isl1, and other genes may play a role in the failure of the lower urinary tract to close. This narrative review outlines the unique anatomy of bladder exstrophy (BE) and epispadias, with a brief mention of the anatomy found in CE. A literature review using PubMed and Google Scholar databases was used to identify relevant articles on the outlined topics without placing any limitations on publication years or study designs. We included full-text English articles published in peer-reviewed journals related to the terms: "exstrophy" & "epispadias" AND "aetiology", "embryology" and "incidence". We summarise the epidemiology of this rare complex - including what is known about its incidence in Africa - before presenting recent advances in comparative genetics from mouse models and human studies that provide insights into BEEC pathogenesis.

Updates on the Care of Cloacal Exstrophy

Cloacal exstrophy is the most severe congenital anomaly of the exstrophy-epispadias complex and is characterized by gastrointestinal, genitourinary, neurospinal, and musculoskeletal malformations. Individualized surgical reconstruction by a multidisciplinary team is required for these complex patients. Not infrequently, patients need staged surgical procedures throughout childhood and adolescence. Following significant improvements in medical care and surgical reconstructive techniques, nearly all patients with cloacal exstrophy now survive, leading to an increased emphasis on quality of life. Increased attention is given to gender identity and the implications of reconstructive decisions. Long-term sequelae of cloacal exstrophy, including functional continence and sexual dysfunction, are recognized, and many patients require ongoing complex care into adulthood.

Prenatal Presentation of a Covered Cloacal Exstrophy Variant; Early Diagnostic Challenges Within the Broad Spectrum of the Exstrophy-Epispadias Complex

There is a broad range of variant phenotypes that can occur within the bladder exstrophy and epispadias complex spectrum. Accurate prenatal detection helps prepare families and to coordinate subspecialty resources. Here, we present the case of a patient with prenatally diagnosed patient with covered cloacal exstrophy variant along with four additional cases illustrating the nonlinear spectrum from isolated epispadias to cloacal exstrophy. Given the rarity of these variants overall and of each subtype within the spectrum, there is a need for long-term multi-institutional outcomes data to improve detection, characterization, and prognostication for these patients.

Exstrophy-Epispadias Complex

Exstrophy-epispadias complex encompasses a spectrum of disorders with lower abdominal midline malformations, including epispadias, bladder exstrophy, and cloacal exstrophy, also known as Omphalocele-Exstrophy-Imperforate Anus-Spinal Anomalies Complex. In this review, the authors discuss the epidemiology, embryologic cause, prenatal findings, phenotypic characteristics, and management strategies of these 3 conditions. The primary focus is to summarize outcomes pertaining to each condition.