The Turkish Journal of Pediatrics 2019; 61: 399-406 Original
DOI: 10.24953/turkjped.2019.03.012
Correlation of the Bayley scales of infant-toddler
development-3rd edition and neuro-sensory motor
assessment in preterm infants during the first year of life.
Özgün Kaya-Kara1, Mintaze Kerem-Günel1, Şule Yiğit2
1
Department of Physiotherapy and Rehabilitation, Hacettepe University Faculty of Health Sciences; 2Department of
Neonatology, 2Hacettepe University Faculty of Medicine, Ankara, Turkey.
E-mail: ozgun.kaya@hacettepe.edu.tr or ozgun_kaya@yahoo.com
Received: 15th July 2018, Revised: 11th October 2018, 2nd December 2018, Accepted: 4th January 2019
SUMMARY: Kaya-Kara Ö, Kerem-Günel M, Yiğit Ş. Correlation of the Bayley
scales of infant-toddler development-3rd edition and neuro-sensory motor
assessment in preterm infants during the first year of life. Turk J Pediatr 2019;
61: 399-406.
The aim of this study was to determine the best cut-off score for determining
motor delay in the Motor Scale of the Bayley Scales of Infant-Toddler
Development-3rd Edition (Bayley-III) when compared to the Neuro-Sensory
Motor Development Assessment (NSMDA) for low birth weight and preterm
infants during the first year of life. One hundred and sixty infants born before
32 weeks of gestation and with birth weights of 1500 grams or less were
included. Classifications of delay using different Bayley-III cut-offs were
cross-tabulated with the NSMDA functional classification. Predictive values
of sensitivity, specificity, positive predictive value, and negative predictive
value were calculated with 95% CIs. The sensitivity of a Bayley-III cut-off
<85 was 100% at 1, 8, and 12 months and 92.3% at 4 months. The best score
on the Bayley-III for identifying infants with mild/moderate/severe motor
problems on the NSMDA was 80 (100% at 1, 4, and 8 months; 91.3% at 12
months). For identifying motor impairments using the Bayley-III in low birth
weight and preterm infants at 1, 4, 8, and 12 months old, the proper cut-off
scores are 80–85.
Key words: infant, assessment, cut-off, Bayley-III, low birth.
Preterm infants (born at less than 37 weeks of the early years of life for early diagnosis in very
gestation) are at risk for neurodevelopmental low birth weight (less than 1500 g) infants
delay. Infants born at a very low birth weight and those born very early (less than 32 weeks
(<1500 g) or born very early (≤32 weeks) are of gestation).4 Defining motor development
considered high risk.1,2 Advances in perinatal of infants in the first year of life is important
and neonatal care over the last 10 years, for ensuring necessary interventions are
including prenatal steroid treatment and the implemented, and increasing evidence
use of exogenous surfactant at tertiary care indicates that this is a critical period for cerebral
centers, have increased the survival rates of development.5 Neuronal differentiation,
preterm infants; however, the rates of motor
including the development of dendrites, axons,
disorders, including cerebral palsy (CP),
neurotransmitter and synapse production, and
continue to be of great concern.3
myelinization, starts during the 2nd trimester
The American Academy of Pediatrics published and progresses rapidly during the first year
guidelines for the follow-up of preterm infants of life.6 Cerebral plasticity is high during
in 2006.4 The guidelines recommended a early infancy, and interventions may be more
neuromotor evaluation at least twice during effective during this period5,7; therefore, it is
, 400 Kaya-Kara Ö, et al The Turkish Journal of Pediatrics • May-June 2019
important to describe, classify, and diagnose between children with normal motor function
neurodevelopmental delays in the first year and those with minimal, mild, moderate, or
of life. While there are several tools available severe motor dysfunction who would benefit
for the evaluation of motor development from treatment. However, the Bayley-III is
in infants during this period, including the a norm-referenced test that assesses the
Prechtl Analysis (GMs), Neurosensory Motor acquisition of fine and gross motor milestones.
Development Assessment (NSMDA), Bayley It has been criticized for overestimating
Scales of Infant-Toddler Development-3rd developmental milestones and also for
Edition (Bayley-III), and the Test of Infant decreasing the number of preterm infants
Motor Performance (TIMP)8,9, the Bayley-III eligible for early intervention.20 The aim of
and NSMDA are the only tools that can be this study, therefore, was to determine the
used throughout these early years.7 best cut-off score for determining motor delay
in the Motor Scale of the Bayley-III compared
Another systematic review evaluating motor
to the NSMDA at 1, 4, 8, and 12 months of age
development during infancy emphasized that
in low birth weight and preterm infants.
the Bayley test is the most common method for
neuromotor and developmental evaluation.7
The Bayley-III, which was developed in 2006, Material and Methods
was updated to ensure the separate calculation
Participants
of composite scores for cognitive, language,
and motor parameters.10 The Bayley-III was The study sample was recruited, and
also updated to provide better information consent was obtained from the Department
for understanding neuromotor development of Neonatology. This cross-sectional study
during early infancy.11 The Bayley-III, while included one hundred sixty children born
one of the most commonly used evaluation before 32 weeks of gestation and with birth
tests, is often impractical in clinical settings weights of 1500 g or less during the first
due to the time required for administration year of life. Infants were excluded if they had
and scoring and the cost of equipment and test congenital anomalies, sensory impairments
forms, which restricts test administration to (e.g., blindness, deafness), chronic lung
psychologists or certain health professionals disease, genetic syndromes, or if they needed
with specialized training. Furthermore, early physiotherapy interventions. The infants
recent evidence has led to worries that the received their routine neonatologist control
Bayley-III may hide developmental delays and during the study period. They were not
overestimate scores.12-14 Of note Anderson
included in any physiotherapy program in
et al.15 performed a recent study of preterm
order to prevent possible effects of therapy on
children using the Bayley-III at 2 years. They
neurodevelopment.
predicted motor outcomes at 4 years with
excellent specificity for motor impairments; Approval was obtained from the local Medical,
however, the sensitivity for motor impairments Surgical, and Drug Studies Ethics Committee
other than CP was low.11 There is growing of the university for this study (Project No:
interest in determining the best cut-off scores LUT 09/168), and all parents provided written
for the Bayley-III because the use of cut-offs informed consent.
has clinical significance for determining motor
impairment within the population.13,16,17 Procedures
The NSMDA is a valid and reliable criterion- The first author (who has 7 years of clinical
referenced test that assesses the quality of experience) underwent a training course
children’s motor development and associated covering the assessments before the study
systems. It uses age-normalized criteria along and administered the Bayley-III and NSMDA.
with functional grading of performance.18,19 Infants were divided into groups of six and
It can reveal differences between normal and assessed first with the Bayley-III or the
abnormal motor development in children. NSMDA. The same infants were assessed
Spittle et al.7 recommended the NSMDA as with the second assessment tool (Bayley-
one of the best assessments for distinguishing III or NSMDA) 1 week later. The order in
