Association between Thyroid Stimulating Hormone and Respiratory Distress Syndrome of Newborn in the Preterm Infants

Abstract Background: Various hormones are known to influence the production and secretion of pulmonary surfactant. But the relationship between respiratory distress syndrome (RDS) and thyroid hormone has yet to be clarified. Methods: 126 infants with gestational age between 24 and 34 weeks who were hospitalized at the neonatal ICU of the Wonju Severance Christian Hospital from April 2017 to February 2019 were included in the study. Infants were divided into 3 groups by gestational age – 24 weeks 0 days to 28 weeks 0 days, 28 weeks 0 days to 31 weeks 0 days, and 31 weeks 0 days to 33 weeks 0 days, each with 18, 34, and 74 subjects, respectively. Among the subjects, there were 56 infants with RDS and 70 infants without RDS.Results: The group with lowest gestational age showed T3 and fT4 level that was lower than those of other groups (p<0.05) on the day of birth but there was no difference in the TSH level (p=0.129). T3 and TSH level were lower in the RDS group compared with the control group on the day of birth (p<0.05). Free thyroxine (fT4) level was higher in the control group on the day of birth but without any significant difference. Multiple logistic regression analysis showed that lower serum TSH levels on the day of birth was associated with a higher incidence of RDS (p<0.05).Conclusion: The incidence of RDS was significantly higher in infants with lower serum TSH levels at birth, but there was no significant difference in RDS incidence according to serum thyroid hormone levels.