{"doi":"10.17615/a9d4-g842","title":"THE ASSOCIATION BETWEEN MATERNAL THYROID FUNCTION AND PRESCHOOL ATTENTION DEFICIT HYPERACTIVITY DISORDER AND EXECUTIVE FUNCTION: EFFECT MEASURE MODIFICATION BY DEIODINASE-ENCODING GENE VARIANTS, MATERNAL SELENIUM AND IODINE INTAKE, AND CHILD SEX","abstract":"Background. Maternal thyroid hormone supply is crucial for fetal neurodevelopment, particularly during the first 20 weeks of gestation when the fetus cannot synthesize sufficient levels of thyroid hormones. Previous studies of maternal thyroid function and child ADHD or executive function have yielded inconsistent results. A number of factors that may modify the association between maternal thyroid function and fetal neurodevelopment have been understudied. First, variants in deiodinase-encoding genes may impact the nature of the association between maternal thyroid function and ADHD because they may alter thyroid hormone concentrations in the placenta or in the fetal cerebral cortex. Second, maternal dietary and selenium intake are crucial for both thyroid hormone synthesis and conversion. Third, fetal sex may impact maternal thyroid function and fetal deiodinase activity. Methods. We estimated the association of maternal thyroid function biomarkers at 17 weeks’ gestation with preschool ADHD and with measures of preschool executive function at 3.5 years. We also assessed effect measure modification by three sets of variables: (1) maternal SNPs in deiodinase-encoding genes DIO1 and DIO2 (rs2235544 and rs225014) and one child SNP in DIO2 (rs225014), (2) maternal iodine and selenium intake, and (3) child sex. We used a nested sub-study of preschool ADHD within the Norwegian Mother and Child Cohort (MoBa) (for the ADHD outcome: N=260 ADHD cases + N=549 representative controls; for the executive function outcomes: N=342). Results. A one-standard deviation increase in maternal free thyroxine index (fT4i) was associated with a 0.10 standard deviation unit increase in parent-rated inhibition (95%CI: 0.01, 0.19), a 0.13 standard deviation unit increase in teacher-rated inhibition (95%CI: 0.01, 0.24), and a 0.13 standard deviation unit increase in parent-rated working memory (95%CI: 0.04, 0.22). We did not detect any main effects of maternal thyroid function on preschool ADHD. Nor did we detect any clear patterns of effect measure modification by maternal or child deiodinase-encoding gene variants, maternal nutrient intake, or child sex. Conclusions. Maternal thyroxine may be uniquely important for fetal neurodevelopment. Although we did not detect a modifying effect of SNPs in deiodinase-encoding genes, more research is warranted given the biological importance of deiodinases in thyroid function.","journal":"UNC Libraries","year":2020,"id":128648,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9593,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":351994,"name":"Samantha S. M. Drover","orcid":null,"position":0,"is_corresponding":true}],"reference_count":209,"raw_metadata":null,"created_at":"2026-07-18T23:15:42.522809Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}