Science Letters

Transient Hypothyroxinemia of Prematurity and Associated Risk Factors: A Review

Sinarinzi Pamela, Monica, Furqan Nasir, Qian Li Juan, Jiang Li*

Department of Pediatrics and Neonatal Intensive Care Unit, Zhongda affiliated Hospital, Southeast University Medical College, 210009, Nanjing, China

Abstract

Preterm infants are greatly at risk of developing a handicap. Major risk factors of such infirmities are linked with low levels of thyroid hormones mostly seen in infants born before 34 weeks. It is referred as transient hypothyroxinemia of prematurity, which is a neonatal endocrine phenomenon that results in early thyroid insufficiency. Transient hypothyroxinemia of prematurity is an easily preventable cause of preemies mental retardation. It is an impermanent postnatal presence of an abnormal insufficient blood concentration of thyroid hormones with a decreased serum thyroxine and free thyroxine, with the exception of a normal thyroid-stimulating hormone level. Its occurrence concurs with the critical period for brain development. The diversity and multifactorial nature of the aetiology of transient hypothyroxinemia of prematurity, namely hypothalamic-pituitary immaturity, loss of maternal serum thyroxine, genetic factors, iodine deficiency and some critical illnesses are among the few of the most important factors that require to be addressed. An increasing collection of evidence has well established the relationship between transient hypothyroxinemia of prematurity and impairments of the growth and development of the brain, which necessitates the implementation of the preventive measure to halt this trend. However, there is an uncertainty among clinicians concerning the most efficient prevention and therapeutic strategies. In this article, we have tried to integrate the present knowledge of the role of thyroid hormones in the developing brain. Moreover, we presented the data linking thyroid hormone status of preterm infants to the neurodevelopment.