Stuttering most often is initiated between the ages of 2.5-4.5. This age is critical both for speech development and the onset of stuttering. Rarely stuttering appears later, at the school age; in adolescents and adults stuttering begins in exceptional cases. What factors determine the stuttering origin and why does one child stutter but another does not? Many speech therapists and physicians know well about the incidents when a sudden fright initiates the stuttering onset. Everyone undergoes stress in childhood, but only a few children, being frightened of a terrible dream, scary dog or an unexpectedly loud sound begin to stutter. Therefore, unexpected fright provoking this disorder in most cases cannot be considered as the reason for stuttering. There exist some risk factors, which initiate stuttering onset after a definite provoking stressful incident. The present study was carried out in an attempt to reveal the preconditions of this disorder. With this purpose, 60 stuttering persons between the ages of 2.4 to 24 were examined and questioned. Data about conditions immediately preceding and accompanying stuttering onset were obtained from the patients, relatives and individual medical case histories. Our findings were as following: In the 1st. group, 24 participants had continuous close contact with stuttering relatives in speech formation period. Stuttering origin coincided with the speech initiation. Most likely the children began to stammer imitating stuttering speech. In the 2nd. group, 36 participants had fluent speech period until the stressful accident initiating stuttering. Thirty three of them had asphyxia neonatorum in anamnesis, 30 had increased cranial pressure during first life months, and 36 had muscle tone disturbances. Children of the 2nd group distinguished by fidgety (28), disturbances of sleep (26), appetite, and digestion (30). Parents reported about fatigability (27), restlessness (29), irritability (29) and timidity (30) of their children. Between the ages of 1.5 - 6, every child survived stress - sudden fright- and began to stutter just after this incidence or during the next 2 weeks. In most cases, children were frightened by dogs, physicians, and darkness.

In a healthy child, the same events could not induce stress and stuttering. The incidents inducing stuttering in children without birth trauma must be substantially more serious. For example, a 13 year-old girl witnessed and spent the night near the dead body of her mother; a 6 year-old girl got into a bombardment; a 4-year-old boy endured painful procedures during 20 days after his surgery. Despite crying and attempting to free himself, he was forcibly immobilized by hospital nurses. These children began to stutter, although none of them had stuttering relatives or endured a birth-trauma. It is quite possible that increased sensibility and timidity of children, who endured asphyxia neonatorum, transforms some events of life into supraliminal irritants that evoke strong stress. This is exactly why not every child began to stutter after the sudden fright, but only those who had certain psychoneurologycal peculiarities because of an endured birth trauma. The complex of neurological and behavioral characteristics of a child after a birth trauma makes stuttering very probable after a strong stress. Thus, we suppose the asphyxia neonatorum is one of the most important, but not exclusive, risk factors of stuttering.