ABR measurement with integration of gestational age
A new approach that enables rapid auditory screening at the maternity for children born prematurely


To reduce the number of false negatives when testing premature babies


Maternity / Neonatology Wards


Illustration recueil des PEA

During a screening ABR test, a sound is sent into the newborn’s ear while electrodes record the physiological response caused by this acoustic stimulation.
This reveals the electrical activity of the auditory pathways, from the auditory nerve to the cerebral cortex.

The typical ABR patterns consist of several waves numbered from I to V. These waves must appear in a range of normality.
Any extension of this latency time for the waves suggests a conduction disorder and requires further investigation.

ABR waves and normality areas
ABR validation on the Babyscreen

The screening test looks at the 5th wave and compares the response obtained with patterns of normalities according to the age of the patient to determine whether the test is validated or not.
As a matter of fact, the auditory pathways are not completely developed at birth and that is why the date of birth of the patient must be precisely informed when the patient is in his first months of growth.
Normality models are not the same at 3 days as at 1 year.

What about children born prematurely ?

Until now only the date of birth allowed to adapt the models of normalities chosen.
However, many studies show that the more the babies are born before full term, the longer the latency of the 5th wave. Indeed their neuronal and auditory systems are not mature. Throughout the first year of their life, newborns will catch up this delay.

Wave five latency graph and gestational age

The latency of wave five is much longer for premature newborns. On this graph, the 5th wave is present at 10ms at 30 weeks of gestation against 7ms for a child born at full term.
If the device uses the patient’s actual age, it will automatically look for the 5th wave around 7ms.
If the newborn is premature, the device will not find a wave in this area of normality and will systematically indicate that the test is not validated.

The ECHODIA research department has taken into account the needs of neonatology teams by creating a unique approach of integration of the weeks of gestation. The device gives the option to indicate the gestational age instead of the actual age and automatically adapts the patterns of normalities.

Nouveau-né prématuré dans une couveuse


Scientific references:
Casali, R. L. and Colellai Dos Santos, M. F. (2010) Auditory Brainstem evoked response: Response patterns of full-term and premature infants, Brazilian Journal of Otorhinolaryngology, 76(6), pp. 729–738.
Jiang, Z. D. et al. (2009) Relative maturation of peripheral and central regions of the human brainstem from preterm to term and the influence of preterm birth, Pediatric Research, 65(6), pp. 657–662.
Gorga MP, Reiland JP, Beauchaine KA, Worthington DW, Jesteadt KA. (1987) Auditory Brainstem Responses from Graduates of an Intensive Care Nursery: Normal Patterns of Response. J Speech Hear Res., 30, pp. 311-318.

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