Urinary Bladder

Abstract

Bladder development is dependent on urine production, so any condition that impairs urine production (such as renal agenesis, severe renal cystic disease, or renal tubular dysplasia) will result in hypoplasia of the bladder. Conversely, the fetal bladder becomes enlarged and hypertrophic in the presence of prolonged obstruction of the bladder outlet or urethra. These pathologic changes should be distinguished from the normal variability of physiologic dilatation, which will also affect the thickness of the wall and its histological appearance. This chapter reviews the normal histologic appearance of the urinary bladder wall throughout gestation, with particular attention to the changes in the muscularis propria during fetal life.