Stuttering rates in pre-school children are more than twice as high as previous reports, new research reveals.
But parents will be pleased to know the same study shows stuttering will not stunt their progress.
In fact, children with the speech disorder are actually more advanced than their peers by the time they reach pre-school.
Contrary to long-held beliefs, the Murdoch Children's Research Institute found stuttering did not have a negative impact on children's language, temperament or mental health.
A Murdoch Children's Research Institute study of more than 1600 children from infancy to 4 years old found the rate of stuttering was 11 percent, which is up from previous estimates of 5 percent.
Lead researcher Professor Sheena Reilly said previous studies may have missed stuttering cases because they did not take into account children under the age of 3. They found that most cases of stuttering occurred between 2 and 3 years of age.
She said the findings should reassure parents that immediate intervention was not necessarily required because it was unlikely to affect their child's language, social and emotional development.
"Parents can be reassured that developmental stuttering is not associated with poorer outcome in the pre-school years at least," Prof Reilly said.
She said it was recommended that parents wait at least 12 months before starting treatment, unless the child had stopped speaking or there was significant concern.
The study also found that recovery rates were low at less than 7 percent. Boys were more likely to start stuttering, but also had higher rates of recovery at 12 months..
"We don't know why recovery rates were so much lower, Prof Reilly said. "Some children seem to grow out of their stuttering or to get better naturally, others get better with treatment," she said.