Developmental Trends in Postnatal Thyroid Hormones and Thyroid Dysfunction in Preterm Infants Born at less than 34 weeks Gestation

Abstract

Objectives

To analyse the trends in thyroid function tests (TFT) in preterm infants, evaluate the frequency of thyroid dysfunction, and identify the factors that influence thyroid function.

Methods

The TFT results and risk factors for thyroid dysfunction in preterm infants with gestational ages (GA) between 25 and 34 weeks were analysed.

Results

In total, 535 infants were enrolled in this study. Thyroid hormone levels vary with gestational and postnatal age, and the total frequency of thyroid dysfunction is 50.3%. Thirty-one infants (5.8%) had delayed TSH elevation. Transient hypothyroxinaemia of prematurity remained significantly associated with both lower birth weight and GA. Congenital hypothyroidism was significantly associated with lower birth weight, 5 min Apgar score, and dopamine use.

Conclusions

Thyroid hormone levels in preterm infants are related to gestation and postnatal age, the frequency of thyroid dysfunction in premature infants is high, and is negatively correlated with GA and birth weight.

Keywords:

• Preterm
• transient hypothyroxinaemia of prematurity
• congenital hypothyroidism
• thyroid function
• delayed TSH elevation

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was supported by the Maternal and Child Nutrition and Health Research Project, National Center for Women and Children’ Health, China CDC (2020FYH015).