Prenatal Detection of Bladder Exstrophy Since the implementation of routine prenatal ultrasound imaging, a great number of medical conditions are now able to be detected prenatally. Among those conditions is classic bladder exstrophy. With the continuing improvement in the quality of ultrasound imaging, technician expertise, and prenatal care, the diagnosis can be now be made more accurately and earlier (even before 20 weeks gestation) then at any time in the past. Unfortunately, there is no single ultrasound finding which predicts the condition accurately 100% of the time. Rather, the diagnosis is typically made by a constellation of findings. The most common finding suggestive of bladder exstrophy is an absence of a urine-containing bladder on consecutive ultrasound studies. The normal fetal bladder fills and empties urine approximately every 1 to 3 hours. As a result, if the first ultrasound does not find a urine-filled bladder but the bladder is actually normal, repeat ultrasound usually will find a normal bladder with urine. In cases of bladder exstrophy or cloacal exstrophy, the absence of bladder filling accurately predicts bladder exstrophy 70—90% of the time. Additional findings suggestive of bladder exstrophy may be seen on the first, as well as subsequent, ultrasound examinations. A defect in the abdominal wall, often with bulging of the bladder through the abdominal wall is seen in between 50% and 80% of affected children. Those patients with classic exstrophy (affecting the urinary system only) also may be noted to have abnormally small penises (males, ~50%), an umbilical cord positioned abnormally low in the abdomen (30%), or widening of the pelvic bones (18%). In addition to the above findings, patients with cloacal exstrophy (affecting both the bladder and intestines) may also be noted to have abnormalities of the spinal cord (70%), kidneys (25%), and lower extremities (25%). While no studies have been performed to date, it is quite possible that with the recent development of three dimensional (3-D) and four dimensional (4-D) ultrasound, the doctor’s ability to accurately detect bladder exstrophy prenatally will continue to improve. While prenatal diagnosis does not change the need for surgical repair after birth, it does make birth planning easier. With the diagnosis made prenatally, parents can seek early consultation with an obstetrician specializing in complex pregnancies and arrange for delivery of their child at a medical center familiar with the care of this medically intricate condition. In addition, consultation with a pediatric urologist can occur prior to delivery. By meeting with a surgeon familiar with the diagnosis of bladder exstrophy and its treatment, parents have the opportunity to discuss their child’s diagnosis, their available options in surgical management, and the anticipated postoperative care required. Although bladder exstrophy represents a rare, but very complex urologic disorder, the ability to make the diagnosis prenatally provides the advantage not only of early referral to physicians familiar with bladder exstrophy, but, most importantly, early diagnosis provides parents the opportunity to be educated early regarding their child’s condition and make informed, unhurried decisions regarding the care of their child. Theodore D. Barber, MD
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