Fetal urology

Normal anatomy of the urinary system. Approximately 85 percent of the general population has one ureter from each kidney. (© 2007 Children's Memorial Hospital)

Staff members in the Division of Urology care for children with disorders of the urinary tract and genitalia. But first a review of normal systems.

Normal anatomy

In a normal urinary system, urine forms in the two kidneys then passes to the bladder through two tubes called ureters . The bladder stores the urine until it is passed via the urethra out of the body. Normally the urine only collects in the bladder and never anywhere else. And in the normal person, urine never flows backward toward the kidneys in any part of the system. A series of valves in the system insures this flow away from the kidneys.

Fetal urological problems

Approximately 15 percent of the general population has two ureters coming from one kidney. In most cases, this causes no problems. (© 2007 Children's Memorial Hospital)

Problems arise when urine does not flow freely through these tubes (this is called obstruction) or when the urine flows backward in the system because of faulty valves (this is called reflux). Both can cause medical problems, and for this reason close attention is paid to the developing urinary system in the baby before birth.

Diagnostic methods

Ultrasound examination can often give clues that reflux and/or obstruction is occurring in the developing baby. Recently, ultrasound machines have been developed that allow us to see details in the developing kidney never before possible. This has allowed us to identify much smaller accumulations of urine in the system, and we are still learning what levels are normal and which suggest problems in development that need correction. Sometimes, Magnetic Resonance Imaging (MRI) is useful for understanding conditions which can't be completely visualized or understood with ultrasound techniques (see more about fetal MRI).

Conditions and findings

Within this section we discuss some of the terms that are used to describe findings or problems in the developing urinary system. Please remember that in some cases our ability to see detail is moving faster than our understanding of what the details mean. Furthermore honest disagreement exists among experts on the meaning of some findings, and older information sources may include beliefs no longer accepted as factual.