Chapter 14.4 - Fetal urinary tract obstruction

Summary

Introduction

Lower urinary tract obstruction (LUTO) is rare and is associated with significant congenital bladder neck obstruction, but also associated with high perinatal mortality and morbidity that tracks into child- and adulthood [1–3]. The underlying pathologies are diverse but, as an isolated problem in a male fetus, posterior urethral valves (PUV) is the commonest cause (approximately 60% of cases), with urethral atresia (UA) also being common (30%) [4]. More complex pathologies exist such as inherited mutations of the anti-muscarinic receptors on bladder smooth muscle causing the megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS). Classically the end-stage clinical presentation is of the prune belly syndrome (PBS), which consists of the triad of deficient or absent abdominal wall musculature, dilation of the proximal and distal urinary tract.

The poor clinical outcomes associated with this disease have led to considerable research, both using animal models and clinically, to further elucidate the underlying pathogenesis of the condition and to evaluate methods of clinical diagnosis, investigation, and triage. From these data, it was hoped that there would be appropriate targeting of antenatal intervention and which intervention would afford the best chance of overall survival but also lead to an improvement in long-term postnatal renal function. This chapter will review the current evidence surrounding these issues.