Association between thyroid dysfunction during pregnancy and neonatal neurodevelopmental outcomes

This study aims to explore the impact of thyroid dysfunction (TD) during pregnancy on the neurodevelopmental outcomes of newborns. Participants were assigned to a thyroid dysfunction group (TDG, <i>n</i> = 92) or a normal control group (NCG, <i>n</i> = 150). Newborns underwent neonatal behavioral neurological assessment (NBNA), and serum thyroid hormone levels, including thyroid-stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3), were measured. Within the TDG, subclinical hypothyroidism accounted for 43.48% (40/92), isolated hypothyroxinemia for 23.91% (22/92), subclinical hyperthyroidism for 17.39% (16/92), overt hypothyroidism for 9.78% (9/92), and overt hyperthyroidism for 5.43% (5/92). The total NBNA score, FT4, and FT3 levels were significantly lower in newborns from the TDG than those from the NCG (<i>P</i> < 0.001), whereas TSH levels were significantly higher (<i>P</i> < 0.05). Neurodevelopmental outcomes differed significantly among the various types of TD (<i>P</i> < 0.05). Correlation analysis showed that the total NBNA score of newborns in the TDG was negatively correlated with TSH level (r = -0.242, <i>P</i> < 0.05) and positively correlated with FT4 and FT3 levels (r = 0.464, r = 0.383, respectively; both <i>P</i> < 0.05). These findings indicate that TD during pregnancy significantly affects the neurodevelopmental outcomes of neonates, with the magnitude of effect varying according to the specific type of thyroid abnormality.