Bed-wetting is involuntary urination during sleep in children over age five. Typically around ages 3-5, children become able to sleep through the night without wetting. While infection or anatomic abnormalities of the urinary system may explain bed-wetting at night, most cases have no explanation and are referred to by doctors as primary nocturnal enuresis (PNE).
Causes
When children are sleeping, the bladder may signal the brain that it is full. But the brain must return a signal for the bladder not to empty. Then the child must wake up and go to the bathroom.
Causes of bed-wetting are varied and may overlap. Contributing factors include:
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Bladder control that develops more slowly than normal
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Greater than average urine production at night
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Genetic predisposition
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A sleep disorder, sometimes related to enlarged tonsils or adenoids
In rare cases, bed-wetting may indicate a physical problem. Usually if a physical problem is responsible, daytime urinary patterns will change as well. Physical conditions that may cause bed-wetting include those in which either excess urine is produced or the bladder does not empty properly:
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Kidney or bladder infections
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Kidney disease
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Diabetes mellitus
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Diabetes insipidus (a very rare disorder in which sugar is normal but excess water is excreted by the kidney)
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Congenital bladder, kidney, or neurological abnormality
Unless a child has one of the conditions listed above, virtually all will stop bed-wetting by the time they reach puberty. However, PNE remains a problem for up to 1% of adults.
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition.
Risk factors include:
Symptoms
The child wakes up and finds the bed wet from urine.
Diagnosis
The doctor will ask about symptoms and medical history, and perform a physical exam. Expect to answer questions about:
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Family history of bed-wetting
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Daytime urinary patterns
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Problems urinating, such as pain or weak stream
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Usual intake of fluids
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Type of fluids consumed
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Presence of blood in the urine
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Strained family dynamics around the issue of bed-wetting
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Child's emotional response to the behavior
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Recent psychologic trauma
Tests may include:
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A Urine Sample--obtained after an overnight fast to determine how concentrated the urine is, and to check for infection and other problems with the urinary tract
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X-rays or Ultrasound Study--if, in rare cases, a physical cause is suspected
The doctor may refer you to one or more specialists. For example: an ear, nose, and throat doctor, if there is evidence of obstructive breathing at night, or a psychiatrist, if there are significant emotional problems.
Treatment
Treatment for PNE aims to gradually reduce the frequency of bed-wetting until the child essentially grows out of it. Treatment is rarely appropriate before age six, which is usually when bed-wetting begins to interfere with social development.
Motivation and Family Support
Bed-wetting is rarely an intentional act. Children are usually upset and ashamed when it happens. Do not punish the child. It is very important that parents offer encouragement that the bed-wetting will stop with time. Do not let siblings tease the child who wets the bed. Keep careful records of the child's progress and offer consistent support.
Behavioral Conditioning
The doctor may recommend a conditioning device, such as a pad with a buzzer that sounds when wet. The child wears the pad in his or her underwear. The alarm wakes the child to get up and use the toilet. Parents may need to help the child get to the bathroom and reset the alarm.
Most studies suggest that this form of treatment has the highest success rate and the fewest complications.
Bladder Training
Some doctors suggest bladder-stretching exercises, but there is little evidence that this approach works. While awake, the child gradually increases the amount of time that elapses between urinations. Do not try this method without talking to the doctor.
Medication
Drugs to treat symptoms include:
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Desmopressin–a hormone nasal spray to decrease the amount of urine produced
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Imipramine–an antidepressant that lightens the level of sleep and may also decrease the frequency of urination
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Anti-cholinergics (oxybutynin and hyoscyamine)–reduce the bladder's ability to contract and void
Prevention
Prevention of bed-wetting in children not prone to PNE is of limited value. Since excess intake of fluid is rarely the cause of enuresis, restricting fluids prior to bed does not produce consistent results. Still, it is reasonable to have all children empty their bladders prior to bed. Some parents wake their children every few hours to urinate, but most report that they rarely get much cooperation.
RESOURCES:
American Academy of Child and Adolescent Psychiatry
http://www.aacap.org
American Academy of Pediatrics
http://www.aap.org
References:
American Academy of Child and Adolescent Psychiatry website. Available at: http://www.aacap.org.
American Academy of Pediatrics website. Available at: http://www.aap.org.
Campbell's Urology, 7th ed. WB Saunders Company; 1998.
Conn's Current Therapy 2001, 53rd ed. WB Saunders Company; 2001.
Lee T, et al. Comparison of effects of treatment of primary nocturnal enuresis with oxybutynin plus desmopressin, desmopressin alone, or imipramine alone: a randomized controlled clinical trial. J Urol. 2005 Sep;174(3):1084-7.
Nelson Textbook of Pediatrics, 16th ed. WB Saunders Company; 2000.
