Newborn Screening

Dr Simon Fraser

Senior Paediatrician (Latrobe Regional Hospital)

Neonatal Advisor(Maternity and Newborn Clinical Network)

Newborn Screening

• Newborn screening (heel prick) test• Hearing screening• Newborn and 6 week examination

Screening – principles

• Serious disorder• Sufficient frequency to be cost effective• Cheap reliable screening test available• Early treatment/intervention beneficial• Consequences of non-treatment severe

Newborn screening (heel prick) test

• Not diagnostic• Follow up testing required for abnormal results• Not every affected child detected• A screened condition that is suspected should

always be tested formally• Timing of sampling important• Infant’s care giver will not be notified if the test

is normal

Conditions screened

• Phenylketonuria (since 1965)• Congenital hypothyroidism (since 1977)• Cystic fibrosis (since 1989)• Various inborn errors of metabolism (since

2002)– MCAD (medium chain acyl CoA dehydrogenase

deficiency most common – Over 20 other rarer conditions

Pre-test procedure

• Parents given information leaflet• Newborn screening test discussed– Screening for many conditions– May have to give second sample– Most second samples within normal range– Parents contacted if further testing necessary

• Consent on screening card (process if refused)• All babies should be tested

Sample collection

• Information completed prior to test• Sucrose for procedural pain management• Blood collected 48-72 hours (not “day 2”)• Capillary blood sampling preferable• All 4 circles need to be completely filled• Air dry in room temperature for 4 hours• Avoid contamination

Special circumstances

• Total parenteral nutrition• Palliated infants• Having received blood products• In utero blood transfusions• Extremely low birthweight or premature

infants• Tables provide guidance for these

Further information

• Neonatal Handbook– www.netsvic.org.au/nets/handbook

• RCH Clinical Guidelines– www.rch.org.au/clinicalguide

• Victorian Clinical Genetic Services– www.genetichealthvic.net.au

• Newborn Screening Laboratory– www.vcgspathology.com.au/NBS

Hearing Screening

• Aims to identify babies born with hearing impairment even if not at risk

• Not diagnostic – positive result requires formal testing

• 1 in 1000 babies have permanent, moderate, severe or profound hearing loss at birth

• Technology easy, quick, reliable and immediate

Benefits of early diagnosis

• Improved language skills• Education• Social development• Emotional development

Process

• Automated auditory brainstem response (AABR)

• Painless• Non-invasive• Both ears checked simultaneously• Takes about 4-7 minutes

Who is screened?

• Statewide• Victorian Infant Hearing Screening Programme• All babies within 1 month of age• Most screened within 2 days of age (can be as

young as 6 hours)• Can be done after discharge• Can be done down to 34 weeks (but usually

closer to discharge)

Risk factors for hearing loss

• Meningitis/encephalitis• Jaundice requiring exchange transfusion• Ventilation > 5 days• Aminoglycoside therapy > 3 days• Congenital abnormality of head/neck• Syndrome known to be related to hearing loss• Close family history congenital hearing

impairment• Maternal infections during pregnancy (TORCH)

Referral to audiology (newborn)

• Diagnostic test• Audiologist• 4 - 6 weeks of age• Referral made by VIHSP Coordinator• Ongoing supports with diagnosis• Reminders in green book at 2, 4 and 8 week

visits (if not already done)

Referral to audiology (infant)

• VIHSP audiology referral form• Can be used if need for assessment has

changed• Discuss hearing screen again at 8 months• Refer if passed newborn screen with risk

factor• Refer if passed newborn screen with no risk

factors but risk factor(s) now developed

Further information

• Neonatal Handbook– www.netsvic.org.au/nets/handbook

• Victorian Infant Hearing Screening Program– www.vihsp.org.au

• MCH Service– www.education.vic.gov.au/mchservice

Newborn and 6 week examination - equipment

• Stethoscope (cleaned)• Ophthalmoscope• Torch• Tongue depressor• Tape measure

Growth

Must measure:• (Birth) weight• (Birth) length• (Birth) head circumference• Plot for gestational age (usually known)• Gestational age assessment charts available• Need to correct for prematurity (if < 37/40)

Abnormal posture, tone, movements

• Floppy• Stiff• Asymmetry (Erb’s palsy)• Jitters• Seizures

Skull/scalp

• Abnormal shape – transient vs. fixed• Fontanelles and sutures • Lumps– cephalhaematoma (common)– congenital malformations (very rare)

• Plagiocephaly

Eyes

• Subconjunctival haemorrhage• Conjunctivitis• Sticky eye• Red eye reflex – must be checked in all babies– Cataracts– White reflex– Pigmented babies

• Unusually large eyes (glaucoma)

Mouth

• Asymmetry – facial palsy, congenital hypoplasia depressor anguli oris (wry smile)

• Natal teeth• Tongue• Cysts• Cleft – only reliable way of excluding a soft

palate cleft is to look

Neck

• Torticollis (sternomastoid ‘tumour’) – usually occurs later

• Cysts• Webbing• Fractured clavicle – lump +/- crepitus

Cardiac examination

• Apex beat• Heaves• Murmurs• Femoral pulses• (Four limb) blood pressure• Heart failure – tachy x2 (-cardia, -pnoea) and

megaly x2 (cardio-, hepato-)

Chest

• Signs of respiratory distress• Colour• Stridor• Wheeze• Symmetrical breath sounds• Added sounds– Wheeze– Crackles

Abdomen

• Organomegaly (ballot kidneys)• Distension• Two vessel cord (association with renal

anomalies)• Omphalitis• Umbilical hernia• Anus (must actively look)

Genitalia

• Male:– Hypospadias (dorsal hood, ventral meatus,

chordee)– Testes– Hydrocoeles

• Female:– Clitoromegaly– Discharge (white, blood)

• Ambiguity

Lower limbs

• Hips:– Risk factors – breech, first degree relative, other

limb deformity, spina bifida– www.ddheducation.com

• Feet:– Talipes – equinovarus and calcaneovalgus– Metatarsus adductus

• Toes:– syndactyly

Examination - actively check

• Measure and plot• Red eye reflex• Cleft palate• Murmurs• Femoral pulses• Hips• Genital abnormalities and ambiguity• Anus