Publication Date:
2016
abstract:
Background: It is often difficult to establish whether
hyperthyrotropinemia in preterm newborn is a simple physiologic
energy sparing phenomenon or a true hypothyroidism requiring
replacement treatment. Objective and hypotheses: This study
aimed to find in what extent thyroid function in the preterm
newborn can be influenced by clinical characteristics and
complications. Method: We studied 35 preterm newborn,
gestational age (GA) 32.0 (2.1) weeks, 21 males, 13 small for
gestational age (SGA), positive at TSH neonatal screening and
with persistent hyperthyrotropinemia during hospitalization.
We collected the following clinical data: GA, type of delivery,
birth weight (BW), length (BL) and head circumference, clinical
complications (RDS, jaundice, infections), time of detection and
level of the pathologic TSH value in the dried blood spot (DBS)
and in the serum sample, time of starting L-thyroxine and its
dosage at steady state. Data are reported as median (IQR). Mann-
Whitney test and simple regression were applied for statistical
analysis. Results: TSH levels and time of detection of pathologic
values were not correlated to GA, BW, length and head
circumference. SGA showed lower serum TSH levels (14.6 (5.1)
mU/ml vs 22.6 (69.9) mU/ml; P!0.05). The patients with RDS
showed lower TSH levels compared with patients without RDS
(14.6 (7.9) mU/ml vs 24.0 (66) mU/ml; P!0.05) and required lower
L-Thyroxine dosage at steady state (6.6 (4.0) vs 10.0 (2.0) mg/kg
per day; P!0.05). The starting time of replacement treatment was
inversely correlated to BW and BL (P!0.05) but was not different
in SGA compared to appropriate for gestational age newborns.
The patients who received replacement treatment had significantly
higher pretreatment TSH in serum (18.11 (65.07) mU/ml vs 11.55
(10.83) mU/ml; P!0.02) but not in DBS (10.0 (23.75) mU/ml vs
6.69 (3.05) mU/ml; PO0.05). Conclusion: Our results support the
hypothesis that subclinical hypothyroidism could play a protective
effect on growth and respiratory function in the preterm newborn.
Further studies are needed to determine whether or not to
undertake replacing therapy.
hyperthyrotropinemia in preterm newborn is a simple physiologic
energy sparing phenomenon or a true hypothyroidism requiring
replacement treatment. Objective and hypotheses: This study
aimed to find in what extent thyroid function in the preterm
newborn can be influenced by clinical characteristics and
complications. Method: We studied 35 preterm newborn,
gestational age (GA) 32.0 (2.1) weeks, 21 males, 13 small for
gestational age (SGA), positive at TSH neonatal screening and
with persistent hyperthyrotropinemia during hospitalization.
We collected the following clinical data: GA, type of delivery,
birth weight (BW), length (BL) and head circumference, clinical
complications (RDS, jaundice, infections), time of detection and
level of the pathologic TSH value in the dried blood spot (DBS)
and in the serum sample, time of starting L-thyroxine and its
dosage at steady state. Data are reported as median (IQR). Mann-
Whitney test and simple regression were applied for statistical
analysis. Results: TSH levels and time of detection of pathologic
values were not correlated to GA, BW, length and head
circumference. SGA showed lower serum TSH levels (14.6 (5.1)
mU/ml vs 22.6 (69.9) mU/ml; P!0.05). The patients with RDS
showed lower TSH levels compared with patients without RDS
(14.6 (7.9) mU/ml vs 24.0 (66) mU/ml; P!0.05) and required lower
L-Thyroxine dosage at steady state (6.6 (4.0) vs 10.0 (2.0) mg/kg
per day; P!0.05). The starting time of replacement treatment was
inversely correlated to BW and BL (P!0.05) but was not different
in SGA compared to appropriate for gestational age newborns.
The patients who received replacement treatment had significantly
higher pretreatment TSH in serum (18.11 (65.07) mU/ml vs 11.55
(10.83) mU/ml; P!0.02) but not in DBS (10.0 (23.75) mU/ml vs
6.69 (3.05) mU/ml; PO0.05). Conclusion: Our results support the
hypothesis that subclinical hypothyroidism could play a protective
effect on growth and respiratory function in the preterm newborn.
Further studies are needed to determine whether or not to
undertake replacing therapy.
Iris type:
Abstract (in Rivista)
Keywords:
Newborn, preterm, hypothyroidism
List of contributors:
Ossola, Serena; Diana, Manuela; Cardani, Roberta; Agosti, Massimo; Salvatoni, Alessandro
Published in: