الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Preterm birth is one of the most significant events in perinatology. An estimated 9.6% of all births are premature. Infants admitted to the NICU have an increased risk of congenital and acquired hearing loss compared to infants admitted to the well-baby nursery.
The auditory system, an important sensory pathway, is strongly associated with the development of language, cognition, and social communication. The axonal connections of human auditory brainstem are established between 16 and 22 weeks gestational age (GA).
Preterm infants, born at a fetal stage within this critical period, might have a different process or pattern from that of full term infants in anatomical and functional auditory brainstem development.
ABR measurement is the most important tool in diagnosing hearing impairment in infants. The ABR in human development first appears around 25 weeks of gestational age. This response matures during the first few years of life, resulting in decreased latencies of most of the response peaks.
The latencies of the most prominent three ABR components (I, III, and V) decrease as a function of gestation, with a maximal shift occurring in the weeks prior to 34 weeks gestation. The maturational changes continue after term, although more slowly, up to approximately 2–4 years of age. Preterm infants are reported to have increased absolute latencies compared to term infants up to 2 years of age.
There is also earlier and clearer identification of peak III compared to peak V in pre-term population which is in line with the peripheral to central maturation of the auditory system.
Sex is another factor that shows inconsistent relations to ABR development.
A special consideration of wave III was taken in some studies, as is it thought to be more characteristic than wave V in preterm infants.
The aim of the work was to:
1. Select the best parameters describing the ABR morphology in full-term infants compared to preterm infant.
2. Select the best electrode montage by comparing the maturation of the ipsilateral and the contralateral pathways.
3. Evaluate wave III and V variations in neonates.
This study is a prospective (Cohort) study that was carried on 50 newborn infants (100 ears).
All the patients fulfilled the following criteria:
1. Age: less than three months (chronological age).
2. Gender: no gender limit
3. Type A tympanometry.
All the newborns included were subjected to the following:
• Detailed history with special emphasis on antenatal, natal, postnatal history and family history such as consanguinity, congenital anomalies, hearing impairment, previous abortion, sibling death and still birth.