The natural history of congenital lower urinary tract obstruction (LUTO) is highly variable and dependent on the gender, severity, duration, and age of onset of the obstruction. Outcome is measured in terms of postnatal survival and is dependent on two factors: pulmonary development and renal function. Complete urethral obstruction or significant restriction of urethral flow results in accumulation of urine within the fetal bladder, leading to marked distention. Prolonged obstruction results in smooth muscle hypertrophy and hyperplasia within the bladder wall, and eventual impairment of contractile capacity as well as compliance and elasticity. Histological studies indicate a progressive dilatation of the distal to proximal renal tubules associated with development of peritubular and interstitial fibrosis. Component of the prenatal evaluation is the serial analysis of fetal urine, obtained by vesicocentesis. More recent studies were designed to focus on the long-term outcomes of children with specific documented urethral obstructions.

The natural history of lower urinary tract obstruction (LUTO) is dependent on the degree of bladder outflow obstruction (complete or partial) and gestational age at presentation. These two factors may be inter-related since complete bladder obstruction is associated with earlier manifestations of the obstructive uropathy. Prenatal ultrasonography is a fundamental method to assess other associated anomalies as well as to evaluate the renal characteristics which are important prognostic factors. MRI may provide more detailed analysis of the urethral obstruction, although it has not been demonstrated to date that this method can determine the underlying etiology of the LUTO. The advantages of fetal cystoscopy may be to permit a more physiological drainage of the obstructed bladder and an endoscopic examination of the dilated posterior urethra allowing the diagnosis of the cause of the obstructive uropathy (posterior urethral valves (PUV) or urethral atresia (UA)).

This chapter reviews conditions occurring in the urinary tract during pregnancy that place the mother, and often the fetus, at risk. Conditions discussed in the chapter that might require surgery during pregnancy include urolithiasis, urinary tract obstruction, accidental and iatrogenic lower urinary tract injury, urethral diverticula, genitourinary fistulas, complications of previous urologic surgery, and urinary tract carcinoma. The normal homeostatic changes involving the urinary tract are frequently responsible for the gravid woman's urinary complaints. The treatment of choice for distal ureteral calculi in pregnant patients who require intervention is cystoscopic examination, followed by either passage of a ureteral stent to relieve obstruction, or ureteroscopy with calculus manipulation. During labor and delivery, the bladder is vulnerable to trauma and injury. Mucosal congestion, submucosal hemorrhage, and capillary oozing around the trigone have been observed cystoscopically after delivery.