Screening for congenital hypothyroidism in extreme premature and/or very low birth weight newborns: the importance of a specific protocol.
BACKGROUND
Neonatal screening for congenital hypothyroidism (CH) in premature infants is not as well established as in term newborns regarding age and number of samples.


OBJECTIVE
1. To evaluate the effectiveness of the protocol recommended by the Neonatal Screening Program of the State of Minas Gerais (PETN-MG) for CH neonatal screening in very low birth weight premature infants. 2. To estimate the prevalence of delayed TSH elevation and thyroid function alterations in the target population.


METHODS
TSH was assessed by ELISA on the 5th, 10th and 30th days of life in all newborns with gestational age <32 weeks and/or very low birth weight (VLB) (<1,500 g) in the period from October 2004 to September 2006.


RESULTS
Out of the 14,462 newborns screened, 2,647 were premature with gestational age <32 weeks and/or VLB. Forty-four cases of altered TSH were found and 11 infants underwent treatment. Delayed TSH elevation was detected in 66% of altered cases. Five out of the 11 cases were detected in the second sample and five cases were only detected in the third sample.


CONCLUSIONS
The high prevalence of thyroid function alterations that demanded treatment (1:242) and delayed TSH elevation in VLB premature infants reinforce the need for a specific protocol, based on retesting procedures, for CH neonatal screening.
Silva
S A B
SA
Postgraduate Program, Minas Gerais Federal University Medical School, Brazil. siura@terra.com.br
Chagas
A J
AJ
Goulart
E M A
EM
Silva
G A B
GA
Marçal
L V
LV
Gomes
M N A
MN
Alves
V M D
VM
D001938:Brazil / Q000453:epidemiology; D003409:Congenital Hypothyroidism / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000592:standards; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D015997:Neonatal Screening / Q000379:methods* / Q000592:standards*; D015995:Prevalence; D013972:Thyrotropin / Q000097:blood
D013972:Thyrotropin