Newborn Screening
Background Information
All babies born in England are offered screening for sickle cell when they are between
5 – 8 days old as part of the heel prick blood tests offered to all new
born babies. The midwife takes the sample from a heel prick using a sterile needle
and blood is spotted onto a blotting paper and sent to the laboratory.
In NW London the sample is sent to Great Ormond Street Hospital (GOSH) and any with
suspected unusual haemoglobin including trait or disease or those with an inconclusive
result are sent to Central Middlesex Hospital (CMH) for a second line test.
In NW London the result of all babies found to have any unusual haemoglobin are
sent to the specialist nurse at Brent Sickle Cell & Thalassaemia Centre.
All newborn babies have a high level of
Fetal Haemoglobin (Hb F)
at birth, this is irrespective of the type of adult haemoglobin they have inherited
from their parents.
If a newborn baby has inherited the genes for normal adult haemoglobin, at birth
the blood test result will indicate the presence of haemoglobins F and A, commonly
written (Hb FA). Haemoglobin A2 is not usually reported in the newborn
screening result, see
Haemoglobin.
Babies with a Carrier (Trait)
In NW London if a child is found to be a carrier (trait) the parents are sent an
appointment letter for the specialist nurse to either visit them at home or to invite
them to a local hospital or centre for counselling in order to explain the result
to them and what the result will mean for their child and for other family members.
If the parents have not been tested they are offered testing in order for them to
know if they are at-risk of having a child with a disease in future. The child’s
older brothers and sisters may or may not be offered testing, this depends on whether
they have been tested before or not, the nature of the unusual haemoglobin found
and whether they are at-risk of having a disease, the parents will be advised accordingly.
If a newborn baby has inherited the genes for an unusual haemoglobin, for example,
sickle cell trait, at birth the blood test result will indicate the presence of
haemoglobins F, A and S, commonly written (Hb FAS); haemoglobin C trait
the blood test result will indicate the presence of F, A and C, commonly written
(Hb FAC).
Babies with an inconclusive result
Sometimes it is difficult for the laboratory to be able to identify the two adult
type haemoglobin that a newborn baby has inherited this is because at birth the
majority of the baby’s haemoglobin is Fetal (baby) Haemoglobin (F) in which
case the baby will need to be retested. Sometimes the baby may have inherited a
novel haemoglobin which is difficult to conform in the early stages of after birth
it may therefore be necessary to retest the baby when he / she is a little older,
usually around four months of age.
In NW London once the baby has been retested the result is sent to the specialist
nurse at Brent Sickle Cell & Thalassaemia Centre. The parents are sent an appointment
letter for the specialist nurse to either visit the parents at home or to invite
them to a local hospital or centre for counselling in order to explain the reason
for the retest; the same heel prick method used for the first test is used for the
retest but instead of using a blotting paper a few drops of blood is put into a
small blood bottle.
Babies with a suspected disease state
Babies with a suspected disease need to be retested in order to confirm the diagnosis.
In NW London the initial result is sent to the specialist nurse at Brent Sickle
Cell & Thalassaemia Centre or to the local specialist nurse. The parents are
sent an appointment letter for the specialist nurse to either visit them at home
or to invite them to a local hospital or centre for counselling in order to explain
the reason for retesting the baby. The same heel prick method used for the first
test is used for the retest but instead of using a blotting paper a few drops of
blood is put into a small blood bottle.
If the child is diagnosed with a disease
If the result confirms that the child has got a disease the parents are seeing again
to inform them of the final result, they are given information about the condition
found, advised on how to care for the child in order to prevent complications and
what to do in an emergency.
If a newborn baby has inherited the genes for a disease, for example, sickle cell
anaemia at birth the blood test result will indicate the presence of haemoglobin
F and S commonly written (Hb FS); or sickle haemoglobin C disease the blood
test result will indicate the presence of haemoglobin F, S and C, commonly
written (Hb FSC), the result will depend on which two haemoglobins the child
has taken from both parent.
The child’s parents are given any recommended educational material available
these will give them more information about the condition and how to look after
their child. If they agree or request it they may be introduced to other parents
who have experience of caring for a child with the same or similar condition to
their child; they are also told about any available local parent’s support
groups and voluntary organisations.
The child’s GP and health visitor are informed of the diagnosis and the child
is referred to the local hospital for specialist care. A hospital appointment is
usually received from the hospital for the child to be seen by the time the child
is two months old; this is in keeping with national standards.
Regular home visits are made by the specialist nurse in order to give the parents
and family on-going education, care and support.
If a child is diagnosed with sickle cell disease
If a child is diagnosed with sickle cell disease the child’s GP is advised
to commence the baby on daily prophylactic Penicillin syrup by 3 months of
age, as research has shown that children with sickle cell disease are unable to
cope with infections caused by pneumococcal organisms, see
Sickle Cell Disease.
In keeping with national recommendations the child’s parents are given a book
entitled ‘Care and management of your child with sickle cell disease – a parent’s
guide’, which gives them detailed information on how to look after their child,
things to avoid to prevent complications and actions to take if the child becomes
unwell. For more information about how to care for a child with sickle cell disease,
see
Resources for the General Public - A Parent’s Guide - Care and Management of Your Child with Sickle Cell Disease,
and details of specialist services available in NW London hospital, see
The Brent Sickle Cell & Thalassaemia Centre.
If a child is at risk or found to have Beta Thalassaemia Major
In NW London if a couple is known to be at-risk of having a child with beta Thalassaemia
major the baby is offered retesting at six weeks old however most babies can be
identified from the newborn sickle cell blood spot screening done at 5 – 8 days
of age. But this test is not meant for identifying babies with Thalassaemia because
the technique used in the laboratory may not identify Thalassaemia that is why it
is important to retest all those known to be at-risk.
If the initial or retest result confirms that the child has beta Thalassaemia major
the parents are given a book entitled ‘What is Thalassaemia?’ produced
by the UK Thalassaemia Society, this gives a lot of information about Thalassaemia,
treatments and how to look after a person with Thalassaemia major.
For further information
Contact the
Brent Sickle Cell & Thalassaemia Centre
or visit the
National Antenatal and Neonatal Screening Programme
website.