Table 3.
Several guidelines on screening for congenital hypothyroidism in preterm or low birth weight infants
| Variable | ESPE* | BSPED/BAPM/UKNSLN | JSPE | ISPAE |
|---|---|---|---|---|
| Released year | 2014 | 2014 | 2014 | 2018 |
| Subjects | Preterm neonates; LBW and VLBW neonates | Preterm infants born at <32 weeks gestation | Premature neonates; infants of birth weight <2,000 g | Preterm; LBW/VLBW infants |
| Timing of 2nd screening test | About 2 weeks of age, or 2 weeks after the first screening test | 28 Days postnatal age or discharge home | One month after birth, when their body weight reaches 2,500 g, or at discharge from the hospital | 4 Weeks of age (or at 2 weeks of age if discharged early) |
| Method of 2nd screening test | Whole blood TSH | Whole blood TSH | Whole blood TSH | Whole blood TSH |
| Comments | The criteria defining a positive screening test result should be adapted for the analytical parameters measured, the method used, and the age at sampling and maturity of the infant. | The policy is based on gestational age criteria. | Infants with delayed TSH elevation in the second mass screening should undergo a detailed examination. | The final TSH cutoffs for preterm, LBW/VLBW infants and twins remain the same as for term infants. (see below†) |
| Hypothyroxinemia in low birth weight infants should not be treated with levothyroxine. |
ESPE, European Society for Paediatric Endocrinology; BSPED, British Society of Paediatric Endocrinology; BAPM, British Association of Perinatal Medicine; UKNSLN, United Kingdom Newborn Screening Laboratory Network; JSPE, Japanese Society for Pediatric Endocrinology; ISPAE, Indian Society for Pediatric and Adolescent Endocrinology; LBW, low birth weight (1,500–2,500 g); VLBW, very low birth weight (<1,500 g); T4, thyroxine; TSH, thyrotropin.
On behalf of European Society for Paediatric Endocrinology, Pediatric Endocrine Society, Latin American Society for Pediatric Endocrinology, Japanese Society for Pediatric Endocrinology, Australasian Paediatric Endocrine Group, Asia Pacific Paediatric Endocrine Society, Indian Society for pediatric and adolescent Endocrinology, and the Congenital Hypothyroidism Consensus Conference Group.
Criteria on venous confirmatory sample results for initiation of levothyroxine therapy in ISPAE guideline: (1) low T4 (<8 μg/dL) or low free T4 (<1.1 ng/dL) irrespective of TSH, (2) mild low T4 (<10 μg/dL) or low FT4 (<1.17 ng/dL) in the presence of elevated venous TSH >20 mIU/L if age is <2 weeks and >10 mIU/L if age is >2 weeks, (3) normal T4/ free T4 with persistently elevated TSH >10 mIU/L at age >3 weeks.