A new form of testing for a rare condition known as Congenital Hypothyroidism in newborn babies has been introduced, The Malta Independent has learnt. 

The condition affects around 2 babies every year but the new test will replace the existing one, which turns out many false positives.

The pilot phase of the national neonatal screening initiative was launched 4 weeks ago and 277 babies have been screened so far. All tests came back negative.

The new system, called newborn blood spot screening, aims to test newborn babies within the first few (3-5) days after birth, for serious childhood conditions (in this case Congenital Hypothyroidism) that have an early onset and if undiagnosed and not treated early enough, may have serious lifetime consequences. 

If untreated, congenital hypothyroidism (anatomic, metabolic, iodine deficiency) may cause growth retardation in babies and children and may result in permanent and severe learning disability. 

It is of utmost importance to diagnosed and treated (with thyroxine) in the first 2-3 weeks after birth in order to avoid neuro-developmental delay.

Until a few weeks ago national screening for congenital hypothyroidism (together with screening for thalassaemia) was performed from umbilical cord blood samples on delivery (day 0), however the current recall rate for this test is high (mainly due to false positives) with between 20-30% of all newborns being called back for re-testing, requiring additional visits to hospital and much anxiety to parents.  The Guthrie heel-prick test, in which a blood spot sample is taken from the baby’s heel when the baby is 3-5 days old, avoids this.

The test measures levels of TSH and FT4.

More accurate timely diagnosis by this method will continue to enable more reliable early evaluation, diagnosis and treatment of the condition.

The introduction of this method of testing which will be done with the mother or guardians signed (informed) consent.  The importance of this screening test and procedure will be explained by the baby’s paediatrician on the mother and baby’s discharge from hospital.  An information sheet with FAQs will be given to each mother. 

The screening test is carried out by the discharge liaison midwives during their first home visit to the mother and 3-5 day old baby following their discharge from Mater Dei and VGH Gozo.

The visiting midwife will collect five drops of blood onto a card by pricking the baby’s heel. 

Private hospitals have been informed about these changes in collection method and will be invited to submit (dried blood spot rather than cord blood) samples to the Pathology laboratory as part of this national neonatal screening initiative.   

As will be explained to parents by the paediatrician and midwife, the screening test is optional, however, highly recommended as it may protect the baby from serious preventable long-term complications.  Mothers/guardians will be asked to sign a consent form to this effect.

If the blood spot test is refused, a venous blood sample must be taken before the baby is 2-3 weeks old.

Uncommonly a venous blood sample may be required to be taken if a neonatal blood spot cannot be processed by the laboratory for technical reasons.

Since the condition is not so common – Malta has an average of two cases diagnosed per year in Malta (1:2200 live births) – most results will be normal.  A small number which will screen positive will be referred to a paediatric endocrinologist for further assessment - a positive result does not automatically indicate a diagnosis of CHT but indicates higher risk requiring immediate attention.

Speaking to this newspaper, Health Minister Chris Fearne said: “Having worked as a pediatric surgeon for over 20 years, neonatal screening is something close to my heart. The previous screening method gave a lot of false positive results which created, in many cases, unwarranted anxiety for many families whose newborn baby was recalled for a further test. The new screening test is much more accurate, removing the need for repeated testing. During these first four weeks of using the heel prick test 277 newborn babies born at Mater Dei, Gozo General Hospital and St James Hospital have been tested for congenital hypothyroidism. Discharge liaison midwives perform the test at home, during their visits to the newborn child.  I want to congratulate and thank the midwives, pediatricians and lab staff who have made this important step towards having healthier children possible."