Offspring conceived through ART have normal thyroid function in adolescence and as young adults

Area of Science:

• Endocrinology
• Reproductive Medicine
• Pediatric Health

Background:

• Previous studies suggest a potential increase in subclinical hypothyroidism in offspring conceived via assisted reproductive technology (ART).
• Maternal estrogen levels after fresh embryo transfers have been hypothesized to influence fetal thyroid function.
• Early detection of thyroid dysfunction is crucial to prevent irreversible neurological damage in young individuals.

Purpose of the Study:

• To investigate potential differences in thyroid function between adolescents and young adults conceived with and without ART.
• To compare thyroid hormone concentrations and prevalence of thyroid disorders in ART-conceived versus naturally conceived individuals.

Main Methods:

• A prospective cohort study (Growing Up Healthy Study) recruited 303 adolescents conceived with ART (aged 13-20 years).
• Thyroid assessments (TSH, fT3, fT4, TPOAb) were compared at ages 14 and 20 years with 2868 naturally conceived controls (Raine Study Generation 2).
• Analysis included comparisons of mean hormone concentrations, prevalence of thyroid dysfunction, and correlation with maternal estrogen levels.

Main Results:

• No clinically relevant differences in thyroid function were observed between the ART-conceived and naturally conceived groups.
• While minor differences in fT3 and fT4 were noted at ages 14 and 20, they were not considered biologically significant.
• The prevalence of euthyroidism, subclinical/overt hypo- and hyperthyroidism, and thyroid autoimmunity did not differ between groups.

Conclusions:

• This study does not support previous findings of clinically significant thyroid function differences in ART-conceived adolescents.
• The minor hormonal fluctuations observed are likely not biologically relevant, suggesting reassuring thyroid health outcomes post-ART.
• Further research is warranted to investigate thyroid function in ART-conceived individuals throughout adulthood.