Transcript Newborn Screening - Dr.Reeta Bora

Dr.Reeta Bora MD,DM(Neonatology)
Astt. Professor of Neonatology
Dept of Pediatrics
Assam Medical College, Dibrugarh
Greetings from Assam Medical College, Dibrugarh
Introduction
 Screening: A brief assessment procedure designed to
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identify those who should receive more intensive diagnosis
or assessment
An attractive approach to preventive medicine
Screening makes sense if–
condition reasonably common,
serious consequences occur if not intervened early,
availability of early & effective intervention
If not used judiciously may damage health, resources
Considering present neonatal health status of Assam, high
risk approach for neonatal screening rather than universal
screening is perhaps a better approach.
Topics to be discussed
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Screening at risk newborn for
Neuro developmental disability
ROP & Visual distubances
Hearing
Screening for Inborn error of metabolism
Neurodevelopmental screening
 Aims at identifying those who need more comprehensive
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evaluation
Why routine screening?
Whom to screen?
Who are high risk Newborn?
Who should screen
What should be the property of screening tests
Screening tests
Follow up
Why routine screening?
Early & accurate detection of developmental problem is
necessary as limited window of malleability of the developing
brain-needs early identification and intervention
 Early intervention leads to better social, adaptive &
intellectual activity
Whom to screen?
 Ideally all infants
time consuming, needs large no of trained person, not
cost effective.
 High risk infants
Who are high risk Newborn?
 Preterm <33 wk GA
 BW<1500 gm
 IVH/PVL
 Asphyxia/Neurological problems
 Persistent/recurrant hypoglycemia
 Ventilated
 Jaundice needing DVET
 Complex medical course
 Sepsis/meningitis
 Multiple CMF/Genetic disorder
Who should screen?
Pediatrician
 Skilled in use of screening techniques
 Actively seek parental concern about development
 Creates links with available resources in the community
Multi disciplinary management needed
 Neurological assessment
 Developmental-intellectual assessment
 Language
 Hearing assessment
 Visual assessment
Properties of a screening test
Best insrtument has
 Adequate sensitivity
 Adequate specificity
 Adequate validity and reliability
 Standardized on various population
 Simple brief, convenient to use, cover all areas of
development
 Culturally sensitive
Neurological assessment
Commonly used method:
 Amiel Tison’s:
 Based on evaluation of active tone & passive tone
 Done at 6wks,3m,6m,9m,12m of age.
 Identifies tone anomalies for early intervention
 Disadvantage: doesn’t assess mental development
Neorodevelopment assessment
Assessment of passive tone
Assesssment of active tone
Neurobehaviour assessment in newborn period
 Brazelton’s neurobehavioral assessment scale
Asses NB behavior on 28 items, scored on 9 point scale
Elicits evidences of cortical control & responsiveness.
 Neonatal Intensive care unit network neurobehavioral
scale(NNNS)
includes
1. Classical neurological items
2. Behavioral items
3. Stress/abstinence items
Developmental screening test after newborn period
 DDST
Has 125well standardized easily administered test item
Age range: 0-6 yrs
sensitivity:0.13 -0.46
 TDSC
Acceptable simple tool
Does not need developmental kit
Age range0-2yrs
sensitivity 0.67, specificity0.79
 Baroda developmental screening test
Has 22 motor & 32 mental items
Easy to use
Gives developmental qotient
Screening for ROP and Visual problems
 PREVELANCE
BW
<1250g
65%
<1000g
80%
 WHOM : < or = 32wk
<1700gm
prolonged oxy admn
 WHEN :
4-6 wk postnatal age
<28wk gestation at 32wk PCA
International Classification of ROP
 Four components
 Location:progression of developing vessels, Zone 1,2,3
 Stage I to V
 Plus disease :Tortuisity & dilataion of vessels
 Extent : Compartments involved
Different stages of ROP
Stage I:
Line of demarcation
Stage IV : Partial retinal
detachment
Stage II : Ridge
Stage III :Ridge with
extraretinal
fibrovascular
proliferation
Stage V : complete retinal
detachment
Treatment: cryo, laser
THRESHOLD ROP
5 OR MORE CONTIGUOUS CLOCK
HRS/8 CUMULATIVE CLOCK HRS
WITH
STAGE 3+ DISEASE IN ZONE ½
RISK OF BLINDNESS IS 50%
TREATMENT REQUIRED
ROP Screen -cont
 If no ROP but retinal vascularization is incomplete re
screen every 2 weeks till complete.
 Mild ROP: Screen wkly
 Monitor all treated till preschool years.
Hearing screen
 Robinette and White cite a number of prevalence studies of
newborn hearing loss which report ranges from 1 per 1000
live births to 6 per 1000 live births.
 Crucial speech and language development begins during
the first six months after birth and is crucial to
development of communication. Therefore, "early
detection and intervention are critical
Screening for hearing
 1896:Use of bell, whistle without child seeing
source(Dr.Thomas Barr)
 1940:Same method remained in practice
 1960-70:Autonomic conditionable response
 1984: Crib o gram
 1990: BERA & OAE
BERA
 Potentials recorded from ear and vertex in response to
brief auditory stimulation to assess the conduction
through auditory pathway upto the midbrain.
Normal Bera
Waveform
I
II
III
IV
V
generators
VIII Nerve
Cochlear nucleus
Superior olivary N
Lateral leminiscus
Inferior coliculi
Normal BERA
 Classic baep consists of 5-8 vertex positive peaks.
 Initial 5 are of clinical interest.
 Obligate BAEP waves are 1,3and 5.
 2,4,6,7 can be absent in some normal subjects, but
absence of any obligate wave is abnormal.[most
common wave to be absent is wave1].
Abnormal BERA
 Obligate wave absence.
 Abnormal absolute or interpeak latencies.
 Amplitude ratio abnormality.
 Significant right to left assymetry[>0.5 ms difference is
significant].
RECORDING ELECTRODES
Screening at 3-6 months more accurate as it excludes
abnormalities due to perinatal conductive deafness
Of neonates coming out of nicu 1-5 %will have sensorineural
hearing loss[stockhord etal 1986].
Clinical Use
INDICATIONS;
 Family history of hearing impairment
 Downs syndrome
 Prematurity with risk factors such as injuries,
meningitis, kernicterus, asphyxia.
 Encephelitis, hydrocephalus,
 Children receiving ototoxic drugs
 Children with intellectual impairment
 Children with chronic middle ear disease
 Screening of neonates coming out of nicu.
NEONATAL NEUROLOGICAL DISEASE AND PROBABLE REGION OF
INVOLVEMENT
HIE
Cochlea,cochlear nucleus, inf
colliculus.
HYPERBILIRUBE
NEMIA
Cochlear nucleus, inf
colliculus, +/- 8th nerve and
cochlea
MENINGITIS
8th nerve
CONGENITAL
8th nerve ,cochlea
VIRAL INFECTION
INTRACRANIAL
HEMORRHAGE
Cochlea
Otoacoustic emissions
 Sounds which arise in the ear canal when (paradoxically)
the TM receives vibrations transmitted backwards through
the middle ear from the cochlea
 First measurement reported in 1978 by David Kemp from
the Institute for Laryngology and Otology
OAE vs BERA
 More easy to perform
 Rapid 2-10 min vs 1.5 hr for ABR
 Less expensive
Sensitivity and Specificity of Two Main Forms of Newborn Hearing
Testing (HEALTH TECHNOLOGY ADVISORY COMMITTEE)
Auditory Brainstem Response (ABR)
Evoked Otoacoustic Emissions (EOAE)
Sensitivity
Specificity
97%-100%
86%-96%
84%
92%
Flow chart for infant with hearing loss
Failed screen(BERA,OAE)
Repeat after 1 m
Diminished
hearing
Diminished
hearing
Normal hearing
Mod sev to profound deafness
Mild/moderate deafness
H aid/speech therapy
speechtherapy
therapy
Hh.Aid
aid/speech
Rpt test 3monthly-exclude progessive hearing loss
Aided audiometry &h.aid
Inadequate help
Cochlear implant
Adequate help-contn rehab
Screening for Inborn Error of
metabolism,endocrinopathies
 IEM –Inherited disorders due metabolic block because
of deficiency of enzyme.
 Not uncommon –needs consideration in d/d of sick
NB
 Early detection has potential for Ry & prevention of
death
 Incidence :1/5000 live
Indian studies
SGRH, Delhi total 393 cases screened
6.7% had IEM
I
Radha Ram et al,IJP,Feb2004
Cong hypothyroidism-1:1700
CAH -1:2575
phenylketonuria:-1:18300
Approach to IEM
 Universal
 At risk-
History of acute deterioration after a period of
normalcy
2. Family h/o consanguinity
3. Progressive illness- cerebral signs
4. Unusual odor
1.
What happens?
A--------B-----/----C
D----------E
Metabolic pathway
Absence of product C
Accumulation of alternate product D or
Accumulation of substrates A
Or intermediates B
clinical features
E.g.:
 Accumulation of substrates : storage disorders,Urea cycle defects
Organic aciduria
 Accumulation of intermediate metabolite: Galactosemia Fructosemia
Tyrosenemia
 Absence of products :Mitochondrial oxidation defects,Fatty acid
oxidation defects
Suspicion
 Clinical
1. Acute illness following a period of normalcy
2. Lethargy or coma
3. Hypotonia, seizures (difficult to control), intractable hiccups
4. Respiratory distress
5. Sepsis or sepsis like illness with no predisposition, E.coli sepsis
6. Vomiting
7. Cholestatic jaundice
8. Unusual odor
Dysmorphic features
10. Organomegaly: hepatomegaly, renomegaly
 Positive family history-----autosomal recessive and X linked
 Unexplained early neonatal deaths
 Parental consanguinity
9.
hypoglycemia
Rule out
sepsis,SGA,IDM,
Syst illness
Non gluc reducing. Subs in urine
positive
negative
galactosemia,HFI
Plasma
ammonia
Urinary ketone
Plasma
FFA
Consider:FAOD
low
high
hepatomegaly
Lowhyperinsulinemia
present
absent
Plasma.lactate
high:GSD1
Plasma hGH,cortisol,T4
Normal-ketotic
hyperglycenemia
Abnormal-endocrinopathy
Collection storage & Transport of sample
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Urine
1.
4.
Routine biochemical test, protein, glucose,reducing subs, pH
Chemical test like DNPH, ferric chloride
Aminoacid chromatography
Organic acid
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Blood
1.
Ammonia-Sample in heparinized vial needs transpotation to lab on
ice immediately.
Lactate-fluoride vial
Galactosemia & tyrosenemia- heparinised
For TMS- Fresh blood in filter paper
2.
3.
2.
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4.
Wilson & Jugner Criteria for
screening(WHO1968)
 Condition must be an important public health
problem
 Clinically & biochemically well defined
 Disorder associated with significant mortality &
morbidity
 Effective treatment available
 Period before onset during which intervention
improves outcome
 Ethical safe simple & robust screening test
 Cost effectiveness of screening test established.
Conclusion
 Technological advance has made possible survival of more
sicker & smaller babies. To have intact survival screening &
intervention of these high risk babies is very important.
 Routine screening for IEM/endocrinopathies before
discharge is desirable but not justifiable at the present
scenario of newborn health in Assam, but availability of
screening tests can be utilized when clinical suspicion is
there.
 Pilot studies are required to know the prevalence of disease
before universal screening programmes.
THANK YOU