Introduction: The objective of our study was to determine the prevalence of a delayed thyroid-stimulating hormone (TSH) rise in infants with congenital hypothyroidism (CH) born in Indiana. Additionally, we sought to determine whether there are differences in clinical or demographic factors associated with this delayed cohort compared to those seen in infants detected early. Methods: Newborn screen (NBS) results were collected for all cases of CH diagnosed between 2012 and 2022. Infants with a delayed TSH rise had an initial normal NBS followed by an abnormal NBS, and a confirmatory serum TSH value >20 mU/mL. Binary logistic regression was performed to identify if demographic and clinical factors (gestational age, birth weight, race, sex, ethnicity, and maternal age) were associated with a delayed rise in TSH. Linear regression was used to assess the relationship between TSH concentration versus selected factors and timing of diagnosis. Results: Seventy-three infants met our inclusion criteria for a delayed diagnosis (16% prevalence). Lower gestational age and birth weight Z scores were associated with higher odds of a delayed TSH rise (each p ≤ 0.001). Lower TSH values were also found to be associated with a delayed diagnosis (p = 0.010). Conclusion: Our study confirms that prematurity is a significant contributing factor for having a delayed diagnosis of CH. In contrast, other demographic factors such as race, sex, ethnicity, and maternal age do not appear to be associated with a delayed diagnosis. Other post-natal factors that may be associated with an increased risk of a delayed rise in TSH in infants with CH require further exploration.

1.
Kaluarachchi
DC
,
Colaizy
TT
,
Pesce
LM
,
Tansey
M
,
Klein
JM
.
Congenital hypothyroidism with delayed thyroid-stimulating hormone elevation in premature infants born at less than 30 weeks gestation
.
J Perinatol
.
2017
;
37
(
3
):
277
82
.
2.
Linder
N
,
Davidovitch
N
,
Reichman
B
,
Kuint
J
,
Lubin
D
,
Meyerovitch
J
, et al
.
Topical iodine-containing antiseptics and subclinical hypothyroidism in preterm infants
.
J Pediatr
.
1997
;
131
(
3
):
434
9
.
3.
Larson
C
,
Hermos
R
,
Delaney
A
,
Daley
D
,
Mitchell
M
.
Risk factors associated with delayed thyrotropin elevations in congenital hypothyroidism
.
J Pediatr
.
2003
;
143
(
5
):
587
91
.
4.
LaFranchi
SH
.
Congenital hypothyroidism: delayed detection after birth and monitoring treatment in the first year of life
.
J Pediatr
.
2011
;
158
(
4
):
525
7
.
5.
Fenton
TR
,
Kim
JH
.
A systematic review and meta-analysis to revise the Fenton growth chart for preterm infants
.
BMC Pediatr
.
2013
;
13
:
59
.
6.
Core Team
.
R: a language and environment for statistical computing
.
Vienna, Austria
:
R Foundation for Statistical Computing
;
2024
.
7.
Harrell
JF
.
Hmisc: harrell miscellaneous
.
R Package Version
.
2024
;
5
:
1
3
. Available form: https://CRAN.R-project.org/package=Hmisc
8.
Harrell
JFE
.
Rms: regression modeling strategies
.
R Package Version
.
2024
;
6
:
8
1
. Available form: https://CRAN.R-project.org/package=rms
9.
Rose
SR
,
Wassner
AJ
,
Wintergerst
KA
,
Yayah-Jones
NH
,
Hopkin
RJ
,
Chuang
J
, et al
.
Congenital hypothyroidism: screening and management
.
Pediatrics
.
2023
;
151
(
1
):
e2022060419
.
10.
Dimitropoulos
A
,
Molinari
L
,
Etter
K
,
Torresani
T
,
Lang-Muritano
M
,
Jenni
OG
, et al
.
Children with congenital hypothyroidism: long-term intellectual outcome after early high-dose treatment
.
Pediatr Res
.
2009
;
65
(
2
):
242
8
.
11.
Zung
A
,
Radi
A
,
Almashanu
S
.
The natural history of congenital hypothyroidism with delayed TSH elevation in neonatal intensive care newborns
.
Clin Endocrinol
.
2020
;
92
(
5
):
443
9
.
12.
Woo
HC
,
Lizarda
A
,
Tucker
R
,
Mitchell
ML
,
Vohr
B
,
Oh
W
, et al
.
Congenital hypothyroidism with a delayed thyroid-stimulating hormone elevation in very premature infants: incidence and growth and developmental outcomes
.
J Pediatr
.
2011
;
158
(
4
):
538
42
.
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