Are Perinatal Risk Factors Helpful in Predicting and Optimizing Treatment Strategies for Transient Hypothyroxinemia in Very-Low-Birth-Weight Infants?

Michelle J. Kantor Herring; Kathleen H. Leef; Robert G. Locke; John L. Stefano; Louis Bartoshesky; David A. Paul

doi:10.1055/s-2003-42691

American Journal of Perinatology, Inhaltsverzeichnis

Am J Perinatol 2003; 20(6): 333-340
DOI: 10.1055/s-2003-42691

Are Perinatal Risk Factors Helpful in Predicting and Optimizing Treatment Strategies for Transient Hypothyroxinemia in Very-Low-Birth-Weight Infants?

Michelle J. Kantor Herring¹ , Kathleen H. Leef² , Robert G. Locke^2,3 , John L. Stefano^2,3 , Louis Bartoshesky^3,4 , David A. Paul^2,3

¹Department of Neonatology, North Shore Medical Center, Miami, Florida
²Department of Pediatrics, Section of Neonatology, Christiana Care Health Services, Newark, Delaware
³Thomas Jefferson University Medical College, Philadelphia, Pennsylvania
⁴Department of Pediatrics, Section of Medical Genetics, duPont Hospital for Children, Wilmington, Delaware

Abstract

ABSTRACT

Transient hypothyroxinemia is common in premature infants and has been associated with intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), poor neurodevelopmental outcomes, and mortality. Recent trials have failed to show that supplemental thyroid hormone improves overall neurodevelopmental outcome. The objective of this article is too determine perinatal risk factors for transient hypothyroxinemia (TH). We studied a cohort of infants born between July 1993 and July 2000 who were less than 1500 g and who received a newborn screening for thyroid function (n = 932). Total serum thyroxine (T₄) was collected routinely on the fifth day of life. T₄ was correlated with gestational age (R = 0.59, p < 0.01). After controlling for potential confounding variables, gestational age, dopamine, and mechanical ventilation were found to be independently associated with low T₄ (overall model: r ² = 0.41, p < 0.01). Number needed to treat (NNT) analysis showed treating all infants less than 27 weeks would lead to treating 6.3 infants for every one with a subsequent T₄ < 5μg/dL. By combining gestational age and need for dopamine support, NNT = 2.4 for every one infant with subsequent T₄ < 5μg/dL. Low gestational age, mechanical ventilation, and need for dopamine were associated with low T₄ levels and may be helpful in optimizing treatment strategies for TH.

KEYWORDS

Thyroxine - transient hypothyroxinemia - prematurity

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Referenzen

REFERENCES

1 Frank J E, Faix J E, Hermos R J. et al . Thyroid function in very low birth weight infants: effects on neonatal hypothyroidism screening. J Pediatr . 1996; 128 548-554
2 Timiras P S, Nzekwe E U. Thyroid hormones and nervous system development. Biol Neonate . 1989; 55 376-385
3 Paul D A, Leef K H, Stefano J L, Bartoshesky L. Low serum thyroxine on initial newborn screening is associated with intraventricular hemorrhage and death in very low birth weight infants. Pediatrics . 1998; 101 903-907
4 Reuss M L, Paneth N, Pinto-Martin J A, Lorenz J M, Susser M. The relation of transient hypothyroxinemia in preterm infants to neurologic development at two years of age. N Engl J Med . 1996; 334 821-827
5 Rapaport R, Rose S, Freemark M. Hypothyroxinemia in the preterm infant: the benefits and risks of thyroxine treatment. J Pediatr . 2001; 139 182-188
6 Crowther C A, Hiller J E, Haslam R R, Robinson J S. Australian collaborative trial of antenatal thyrotropin-releasing hormone: adverse effects at 12-months follow-up. ACTOBAT Study Group. Pediatrics . 1997; 99 311-317
7 van Wassenaer A, Kok J H, de Vijlder J J. et al . Effects of thyroxine supplementation on neurologic development in infants born at less than 30 weeks' gestation. N Engl J Med . 1997; 336 21-26
8 Ballard J L, Khoury J C, Wedig K, Wang L, Eilers-Walsman B L, Lipp R. New Ballard score, expanded to include extremely premature infants. J Pediatr . 1991; 119 417-423
9 Northern Neonatal Nursing Initiative. Systolic blood pressure in babies less than 32 weeks gestation in the first year of life. Arch Dis Child Fetal Neonatal Ed . 1999; 80 F38-F42
10 Paul D A, Leef K L, Voss B, Stefano J L, Bartoshesky L. Thyroxine and illness severity in very low birth weight infants. Thyroid . 2001; 11 871-875
11 Uhrmann S, Marks K H, Maisels M J, Kulin H E, Kaplan M, Utiger R. Frequency of transient hypothyroxinemia in low birthweight infants. Arch Dis Child . 1981; 56 214-217
12 Leviton A, Paneth N, Reuss M L. et al . Hypothyroxinemia of prematurity and the risk of cerebral white matter damage. J Pediatr . 1999; 134 706-711
13 Marsh T D, Freeman D, McKeown R E, Bowyer F B. Increased mortality in neonates with low thyroxine values. J Perinatol . 1993; 13 201-204
14 Vanhole C, Aerssens P, Naulaers G. L-Thyroxine treatment of preterm newborns: clinical and endocrine effects. Pediatr Res . 1997; 42 87-92
15 Chowdry P, Scanlon J W, Auerbach R, Abassi V. Results of controlled double-blind study of thyroid replacement in very low-birth-weight premature infants with hypothyroxinemia. Pediatrics . 1984; 73 301-305
16 Briet J, van Wassenaer A, Dekker F W. et al . Neonatal thyroxine supplementation in very preterm children: developmental outcome evaluated at early school age. Pediatrics . 2001; 107 712-718
17 Smith L, Leake R, Berman N, Villanueva S, Brasel J. Postnatal thyroxine supplementation in infants less than 32 weeks' gestation: effects on pulmonary morbidity. J Perinatol . 2000; 20 427-431