What are congenital anomalies of the bladder and genitalia?
A congenital anomaly is another name for a birth defect, which is a condition present at birth that can cause health problems or affect how the body works.
Congenital anomalies often affect the genitalia, which include the internal and external reproductive (sex) organs and the urinary bladder and urethra.
What are some common congenital anomalies of the bladder?
Exstrophy: The bladder, bony pelvis, and muscles of the lower abdomen fail to fold together during embryonic life. In the most common form of exstrophy, the child is born with the bladder exposed to the exterior of the lower abdomen and the urethra fails to develop. Several variations of exstrophy exist, including epispadias (where the urethra does not fold together) or cloacal exstrophy (where both the bladder and the bowel are exposed in the lower abdominal wall).
This condition occurs in about one of every 200,000 live births. It occurs somewhat more in boys than in girls. Bladder exstrophy is usually treated with surgery shortly after birth. First, the bladder and associated structures are closed, then the genitalia are reconstructed. Most patients with this condition have ongoing urological and genital issues that require close follow up in adulthood. Often, repeat surgeries are needed later in life to address issues like urinary incontinence, urethral strictures, or reflux of urine up to the kidneys.
Posterior urethral valves (PUV): This condition, only seen in males, results from failed regression of valves in the urethra during embryonic life. This impairs bladder emptying during fetal development. PUV may have profound post-natal effects on bladder and kidney function, as well as lung development. This disorder can be very severe immediately after birth, or may not even be diagnosed until later in adolescence or adulthood.
Patients with PUV have exceptionally high rates of kidney deterioration in adult life. It is estimated that approximately one-third of these patients may develop a need for hemodialysis or a kidney transplant by the time they reach early adulthood. This is even more common as they progress through adult life. Close follow-up with a nephrologist (kidney specialist) and a urologist is recommended to follow kidney function and bladder function as the boy develops into adulthood and beyond.
Vesicoureteral reflux (VUR) and ectopic ureters: This group of conditions relates to abnormalities of insertion of the ureters (tubes that drain from the kidneys to the bladder) into the bladder. In a normally developed bladder, the ureters pierce the back wall of the bladder and travel through it indirectly to create a valve mechanism that closes off as the bladder fills. This prevents the reflux of urine from the bladder up to the kidneys. When that tunnel is too short, reflux may occur. This condition increases the risk for kidney infections (known as pyelonephritis), kidney scarring, and possibly long-term kidney deterioration.
Management usually involves close monitoring with kidney ultrasounds and bladder X-rays. Often, there is a need for behavioral modifications in toileting, sometimes daily antibiotics, and sometimes surgery. In some situations, the ureter fails to insert into the bladder altogether and may insert into the vagina, perineum (area between the scrotum or vulva and the anus), or (in males) the seminal vesicle, prostate, or rectum. These situations may be diagnosed before birth or after birth when a child experiences repeat infections or persistent urinary leakage after potty training. Unlike most other conditions, ureteral abnormalities are not very often causes of trouble in adult life.
Definitive management with surgery is the norm in childhood. Female patients who develop kidney scarring and dysfunction from VUR may be at a higher risk for kidney failure during pregnancies and need to be closely watched and counseled.
Congenital neurogenic bladder: Inborn conditions that affect the brain and spinal cord often can have a profound effect on bladder function. The most common causes of congenital neurogenic bladder are:
- Spina bifida: Incomplete closure of the spinal column, which can cause nerve damage or paralysis in areas of the body below the spinal lesion.
- Sacral agenesis: A condition in which part of the spine fails to develop.
- Cerebral palsy: Damage to areas of the brain responsible for muscle control.
In spina bifida and sacral agenesis, the bladder is known to change through the patient’s life. Most commonly, the bladder may shrink and show spasticity that can lead to urinary incontinence and urinary infections. Importantly, the bladder may store urine at high pressures, a condition that risks kidney damage.
Close medical surveillance is required, often in the form of clinics that provide multiple medical specialists. Urological surveillance includes a combination of kidney ultrasounds, occasionally other radiologic studies of the bladder, and specialized testing known as urodynamics. Urodynamics requires a small catheter (a thin, flexible tube) with a pressure monitor be placed in the bladder. The catheter measures bladder filling and emptying pressures as the bladder is slowly filled with fluid.
Treatments for congenital neuropathic bladder typically have the goal of urinary continence or lowering bladder storage pressures. These include oral medications, initiation of self-catheterization, injections of Botulinum toxin (Botox®) into the bladder or urinary sphincter, or surgery to increase the size of the bladder (known as augmentation cystoplasty) or tighten the urinary sphincter.
What are some common congenital anomalies of the genitalia?
A fetus will develop as a female unless otherwise directed to become male. The direction to become male comes from androgen (male hormones) produced by the testes that form when a Y chromosome is present (males have XY chromosomes and females have XX chromosomes). Therefore, the amount and timing of sex hormones, along with possible errors in how cell receptors respond to sex hormones, play a large role in the development of genital anomalies.
Common congenital anomalies of the genitalia include:
Cryptorchidism: One or both testes remain in the abdominal cavity, having failed to move down into the scrotum. The condition is found in about 30% of premature and 4% of full-term male births. Surgery can be performed to move the testes into the scrotum. If left untreated, cryptorchidism is linked to a higher occurrence of testicular tumors and sterility.
Hypospadias: The urinary meatus (opening) forms somewhere along the underside of the penis instead of at the tip. This is the most common abnormality of the penis, affecting one to eight of every 1,000 newborn boys. Males with this condition may also have a curved penis or an abnormality of scrotal development. Surgical repair can close the misplaced opening and create a new one where it should be, and is typically done before the age of two. Surgery to address curvature or urethral blockage after the child advances through puberty are well-described in patients who have had hypospadias repairs, and in those who were not repaired in childhood.
Epispadias: The urinary opening forms somewhere along the top or side of the penis. This is a variation of bladder exstrophy and is typically more severe than hypospadias because the bladder sphincter mechanisms are usually affected, causing leakage of urine. This condition is much more rare than hypospadias, with an estimated rate of one in every 300,000 newborns.
Disorders of sexual development (DSD): Many conditions in which there is a mismatch between the appearance of the external genitalia and the genetic definition of male and female. Most commonly, the external genitals at birth appear neither distinctly male nor distinctly female (“ambiguous genitalia”). In other situations, the external genital anatomy may appear as “male” but the internal sexual organs are “female” (or vice versa). Newborn evaluation requires a multidisciplinary approach that includes endocrinology and urology at a minimum.
It is estimated that about one of every 1,500 to 2,000 births results in genitalia that are unusual enough to demand the attention of a sex differentiation expert. However, many other people are also born with variations in sex anatomy that are very slight or may not even show up until later in life. Ongoing problems after puberty are often experienced when the patient initiates sexual life or desires to start a family, and these may require medical or surgical intervention.
The following are the most common disorders of sexual differentiation:
- Androgen insensitivity syndrome (AIS): An inherited condition in which the body’s cells are unable to respond to male hormones. In this condition, the external appearance is either female or ambiguous, despite the patient having XY sex chromosomes.
- Partial androgen insensitivity syndrome (PAIS): This condition is similar to AIS, but often the child is less severely affected and the genital appearance is typically ambiguous.
- Congenital adrenal hyperplasia (CAH): A group of conditions that all effect steroid synthesis in the adrenal glands. While many variations can exist depending on the genetic sex, the most commonly recognized form is male external genital appearance, but female internal genital organs and genetic make-up (XX). Some patients with CAH may also have a potentially life-threatening inability to regulate salt and water. Newborn screening for CAH is now standard due to the risk associated with delay in diagnosis.
- Ovotestes (previously known as “true hermaphroditism”): Presence of both ovaries and testes in the same person. The person’s genitalia and overall appearance may be that of either male or female, or ambiguous. One risk of the condition is an increased risk of gonadal cancer unless the abnormal gonadal tissue is surgically removed.
What causes congenital anomalies of the bladder and genitalia?
Most causes of congenital anomalies are unknown, but genetic (inherited) mutations and environmental exposures are the cause in some cases.
There are a great number and variety of congenital anomalies of the bladder and genitalia, as well as different degrees of severity. Structural malformations, duplications, and failures to develop are all possibilities.