Thyroid hormones for preventing neurodevelopmental impairment in preterm infants

Area of Science:

• Neonatal Medicine
• Pediatric Endocrinology
• Clinical Trials

Background:

• Transient hypothyroxinemia in preterm infants is linked to adverse neurodevelopmental outcomes.
• Thyroid hormone therapy is a potential intervention to mitigate this morbidity.

Purpose of the Study:

• To evaluate the efficacy and safety of thyroid hormone therapy in preterm infants without congenital hypothyroidism.
• To assess impacts on neonatal and long-term neurodevelopmental outcomes, including benefits and harms.

Main Methods:

• Systematic review and meta-analysis of randomized and quasi-randomized controlled trials.
• Inclusion of studies comparing thyroid hormone therapy (thyroxine or triiodothyronine) versus control in preterm infants (< 32 weeks gestation).
• Primary outcomes included mortality and neurodevelopmental measures (e.g., Bayley Scales, cerebral palsy).

Main Results:

• Meta-analysis of five studies showed no significant difference in mortality.
• No significant differences were observed in neurodevelopmental outcomes (Bayley MDI/PDI) at 7-12 months or 24 months.
• One small study suggested reduced oxygen requirements with triiodothyronine, but overall, respiratory outcomes were not improved.

Conclusions:

• Current evidence does not support routine thyroid hormone use in preterm infants to improve mortality or neurodevelopment.
• Limited trial size and power restrict definitive conclusions; further large-scale trials are warranted.
• Future research should focus on specific subgroups, like infants < 27 weeks gestation, and prespecified outcomes.