Newborn
Screening : Optional or Obligation?
Dr.
Mallikarjuna Swamy, MBBS, DNB (Pediatrics), Clinical Fellow (Neonatology)
Department
of Pediatrics, Alia International Hospital, Mahboula
“Marhaba….”
Overview
Newborn screening is the practice of screening every newborn for
certain genetic, endocrine, and metabolic conditions, as well as functional
disorders that are not apparent at birth. Finding these conditions soon after birth can help prevent
some serious problems, such as brain damage, organ damage, and even death,
thereby enabling the children to reach their full potential.
For example, babies are tested for hypothyroidism, which means that their
bodies do not make enough thyroid hormone. Babies with hypothyroidism can take
medication with the hormone to avoid the slowed growth and brain damage that
can happen if their hypothyroidism is not treated.
Screening tests do not diagnose
illnesses. They identify which babies need additional testing to confirm or
rule out illnesses. If follow-up testing
confirms that the child has a disease, appropriate treatment can be started
right away, before symptoms appear.
Newborn screening checks for
serious but rare conditions at birth. It includes blood, hearing, heart and hip
screening.
Blood
Test:
Newborn screening samples are
collected from the infant between 24 hours and 7 days after birth, with the
requirement that the baby has fed at least once.
A health professional will take a
few drops of blood from the baby’s heel. The blood is collected on a specially designed filter paper
and sent to a Newborn
screening lab for testing. Thanks to improved laboratory techniques that
require smaller sample volumes and improved automated heel lancing devices that
minimize trauma and pain.
Conditions
Tested:
The most thorough screening panel
checks for about 40 disorders that include sickle cell disease and other hemoglobin disorders,
conditions where a child is unable to process certain nutrients (such as PKU),
or conditions where there is a hormonal insufficiency (such as
hypothyroidism).
All the Newborn screening laboratories
screen for the six major conditions (among the big list of around 40 screened parameters) which
can be either treated or kept under control – Congenital Hypothyroidism,
Galactosemia, G6PD Deficiency,
Congenital Adrenal Hyperplasia, Hemoglobinopathies and Cystic Fibrosis.
Screening
Results
If the results are "negative"
("pass" or in-range result) it means that the baby’s test results
did not show signs of any of the conditions included in the screening.
If
the results are "positive" ("fail" or out-of-range
result) it means that the baby’s test results showed signs of one or more
of the conditions included in the newborn screening.
This does not always
mean that the baby has the condition. It may just mean that more testing is
needed.
Ø The
doctor might recommend that the child get screened again or have more specific
tests to diagnose a condition.
Hearing Screening:
·
All babies should be screened for
hearing loss no later than 1 month of age. It is best if they are
screened before leaving the hospital after birth.
·
If a baby does not pass a hearing
screening, it's very important to get a full hearing test as soon as possible,
but no later than 3 months of age.
Two different tests can be used to screen for hearing
loss in babies. Both tests are quick (5-10 minutes), safe and comfortable (not
painful). In fact, these tests are often performed while a baby is asleep. One
or both tests may be used.
1. Otoacoustic Emissions (OAE) Test: This test is used to determine if
certain parts of the baby’s ear respond to sound. During the test, a miniature
earphone and microphone are placed in the ear and sounds are played. When a
baby has normal hearing, an echo is reflected back into the ear canal, which
can be measured by the microphone. If no echo is detected, it can indicate
hearing loss.
2. Auditory Brain Stem Response (ABR) Test: This test is used to evaluate the
auditory brain stem (the part of the nerve that carries sound from the ear to
the brain) and the brain’s response to sound. During this test, miniature
earphones are placed in the ear and sounds are played. Band-Aid-like electrodes
are placed along the baby’s head to detect the brain’s response to the sounds.
If the baby’s brain does not respond consistently to the sounds, there may be a
hearing problem.
Screening
for Critical Congenital Heart Defects:
Babies with a critical congenital
heart defect (CCHD) are at significant risk of disability or death if their
condition is not diagnosed soon after birth.
CCHDs can
potentially be detected using pulse
oximetry screening, before they show signs of the
condition.
Pulse oximetry screening is most likely to
detect seven of the CCHDs. These seven main screening targets are hypoplastic
left heart syndrome, pulmonary atresia (with intact septum), tetralogy of
Fallot, total anomalous pulmonary venous return, transposition of the great
arteries, tricuspid atresia, and truncus arteriosus. (Other heart defects can
be just as severe as the main screening targets and also require treatment soon
after birth. However, pulse oximetry screening may not detect these heart
defects as consistently as the seven disorders listed as the main screening
targets.)
When and How Babies Are Screened
Pulse
oximetry is
a simple bedside test to determine the amount of oxygen in a baby’s blood
and the baby’s pulse rate. Low levels of oxygen in the blood can be a
sign of a CCHD. The test is done using a machine called a pulse
oximeter, with sensors placed on the baby’s skin. The test is painless
and takes only a few minutes.
Screening is done when a baby is 24 to 48 hours
of age, or as late as possible if the baby is to be discharged from the
hospital before he or she is 24 hours of age.
Pulse oximetry screening does not
replace a complete history and physical examination, which sometimes can detect
a CCHD before the development of low levels of oxygen in the blood. Pulse
oximetry screening, therefore, should be used along with the physical
examination.
CCHD
Screening Results
If
the results are “negative” ("pass" or in-range result), it
means that the baby’s test results did not show signs of a CCHD. This type
of screening test does not detect all CCHDs, so it is possible for a baby with
a negative screening result to still have a CCHD or other congenital heart
defect.
If
the results are “positive” ("fail" or out-of-range result), it
means that the baby’s test results showed low levels of oxygen in the blood,
which can be a sign of a CCHD. This does not always mean that
the baby has a CCHD. It just means that more testing is needed.
The baby’s doctor might recommend
that the infant get screened again or have more specific tests, like an echocardiogram (an
ultrasound picture of the heart), to diagnose a CCHD. Once identified, babies
with a CCHD can be seen by cardiologists and can receive special care and
treatment that can prevent disability and death early in life. Babies who are
found to have a CCHD also might be evaluated by a clinical geneticist. This
could help identify genetic syndromes associated with CCHDs and inform families
about future risks. Certain hospitals
routinely screen all newborns for CCHDs.
Screening for Developmental
Dysplasia of the Hip:
Developmental
dislocation of the hip can lead to premature degenerative joint disease,
impaired walking, and pain. Surgery is often necessary once these complications
have occurred. Hip instability can be treated non-surgically if it is
detected early. Neonatal screening, which has been practiced for almost
four decades, is intended to reduce the need for surgery, prevent degenerative
joint disease, pain, and mobility limitations.
Nonspecific
instability in the hip is a common finding in newborns. More than 80% of clinically unstable
hips noted at birth have been shown to resolve spontaneously. However, due to the potential for
subsequent impairment and the widespread belief that earlier treatment leads to
improved outcomes, screening newborns for DDH has become commonplace.
The most common methods of screening for DDH involve the
physical examination of the hips and lower extremities. Ultrasonography during the first 4 weeks of life often
reveals the presence of minor degrees of instability which will not be apparent
on physical examination and may resolve spontaneously without treatment. X-ray is less accurate in the first 3–4 months of life, when
the bones of the hip are not completely ossified.
When and How Babies Are Screened
- All newborns should undergo a hip examination prior to discharge from hospital.
- High risk infants should be booked for an Ultrasound at 6 weeks of age.
- If an examiner is unsure of the stability of an infant’s hip/s, re-examination by an experienced clinician should be sought.
- Hip examination should occur at birth, 6-8 weeks and 6 months of age
- At risk infants should undergo hip examination at all well consultations.
- Any child with a dislocatable hip should be referred immediately to an Orthopaedic Surgeon or Paediatrician.
Selective screening should include newborns with
risk factors for DDH, namely
- a family history of DDH
(confined to at least one first degree relative or two second degree
relatives treated for DDH)
- breech presentation, foot
deformities
- positive/equivocal clinical
findings
Concerns
regarding an infant’s hips should be acted on immediately – delays in treatment
may have adverse effects on the outcomes for the infant.
Newborn
Screening - Get Help!
If your baby’s newborn screening
tests show that there could be a problem, work with your baby’s doctor to get
any needed follow-up tests as soon as possible – don’t wait!
Finding and treating some of the
conditions at an early age can prevent serious problems, such as brain damage,
organ damage, and even death. Many of the conditions can be treated with
medication or changes to the baby’s diet.
If one of your children has a health condition,
will another have it, too?
- Almost all of the health conditions found by newborn screening are inherited. This means they are passed from parents to children.
- When one child in a family has an inherited health condition, the chance of a brother or sister having the same condition is higher than if no child in the family has the condition.
- If you have a child with a health condition and you want to have another baby, talk to your health care provider or a genetic counselor. A genetic counselor is a person who is trained to know about genetics, birth defects and other medical problems that run in families.
- Sometimes hearing loss is not inherited. For example, it can be caused by an infection during pregnancy. In this case, it usually doesn’t happen in another pregnancy.
Newborn Screening at Alia
International Hospital:
We routinely screen the babies born in our hospital with above
mentioned Screening panel after consenting with the parents before
discharge.
Though Newborn screeing is still optional in most of the
countries, parents must view this as an obligation for carving the better
future of their baby.
mallikarjuna78@gmail.com
Useful websites:
http://emedicine.medscape.com/article/1413486-overview#aw2aab6b4 - for Heel sticks
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