Relationship between thyroid hormone levels and transient tachypnea of the newborn in late-preterm, early-term, and term infants.

PURPOSE: We aimed to investigate the association between thyroid hormone levels and transient tachypnea of the newborn (TTN) among late-preterm, early-term, and term infants admitted to neonatal intensive care unit (NICU).

MATERIALS AND METHOD: In the current retrospective study, neonates admitted to the NICU due to TTN were assigned to the TTN group (n = 404). Healthy neonates who were followed up in the well-baby nursery comprised the control group (n = 7335). Infants were grouped by gestational age into late-preterm (34-366 weeks), early-term (37-386 weeks), and term subgroups (39-416 weeks). Serum levels of thyroid-stimulating hormone (TSH) and thyroxin (T4) were determined from venipuncture samples taken at least 48 hours after birth. The relationship between thyroid hormone levels and the need for NICU admission for TTN was compared between groups.

RESULTS

Compared to control infants, term neonates with TTN had significantly higher TSH levels, whereas late-preterm and early-term neonates with TTN had significantly lower T4 levels. Birth weight and mode of delivery had no effect on NICU admission for TTN.

CONCLUSIONS

Infants admitted to NICU due to TTN had significantly different thyroid hormone levels with differences depending on gestational age.