Toddlers who become dry at night can probably thank luck and possibly their parents for taking them out of night-time nappies/pull-ups at an early age.

The Child who's never been dry at night

If you have noticed your child's pull-up is drenched in the morning, this could be due to not having a natural rise in the level of a particularly hormone at night.  This hormone is a chemical messenger from the brain to the kidneys which tells them to slow down making urine.  It's called ADH (anti-diuretic hormone).  One of the reasons most of us get a good night's sleep is that our ADH levels go up at night, so our kidneys produce less urine.  This increase in ADH may not occur to the same extent in some children with a bedwetting problem.

A BIG STEP IN LIFE... THE DEVELOPMENT OF BLADDER CONTROL IN CHILDHOOD

Birth and Infancy...recent studies have shown that voiding (bladder emptying) happens in response to various bladder volumes and may involve complex nerve pathways.

1-2 years... becomes more aware of full bladder.

3 years... is able to hold urine for longer and longer periods (this increases the bladder's ability to hold larger volumes of urine).

3-4 years... is able to empty bladder into a toilet when the bladder is full.  The majority of children will achieve daytime dryness during this year.

4 years... can stop passing urine when child wishes - the majority of children will be dry on most nights.

6 years... can pass urine regardless of whether the bladder is full (ie. the age at which it's realistic to say "I want you to go to the toilet for a wee before we get into the car").

Bedwetting is common...

In a school class of 30:

  • at the age of five there will be five or more children in the class who are still wetting the bed at least twice a week
  • at the age of seven, there will be about two in the class who are still wetting the bed at least twice a week
  • at the age of 10 there will be one or two
  • in the first year of secondary school there will be one
  • in Year 10 (15 years olds) there will be one in every two classes 

Bedwetting in a child who's never been dry... is NOT caused by:

  • laziness or rebelliousness
  • sleeping deeply (this can just make bladder training more of a challenge)

...is HARDLY EVER caused by

  • a small bladder
  • hidden illness
  • being emotionally upset

...is MOST COMMONLY caused by

  • difficulty arousing from sleep in response to a full bladder
  • the production of more urine at night than the bladder can store
  • a family history of bedwetting

Changing or Stopping things known not to be helpful

  • Don't retstrict fluids in the evening (unless bedtime drinking is excessive).
  • Avoid routinely waking the child to empty their bladder.
  • Be careful about incentive schemes for your child.
  • Don't make the cleaning up process a punishment for the child.
  • Encourage the child to drink lots of fluids throughout the day.

As a GENERAL rule, children should be drinking ABOUT 6-8 glasses of fluid a day, but they should certainly drink whenever they feel thirsty.  The fluid intake should be spread fairly evenly over the day.

In the child aged seven or more, it is worth trying the bed alarm.  

Source: The Dry Night, Continence Foundation of Australia