RT Journal Article SR Electronic T1 Maternal mild thyroid dysfunction and offspring cognitive and motor development from infancy to childhood: the Rhea mother–child cohort study in Crete, Greece JF Journal of Epidemiology and Community Health JO J Epidemiol Community Health FD BMJ Publishing Group Ltd SP 29 OP 35 DO 10.1136/jech-2019-213309 VO 75 IS 1 A1 Mariza Kampouri A1 Katerina Margetaki A1 Katerina Koutra A1 Andriani Kyriklaki A1 Polyxeni Karakosta A1 Despoina Anousaki A1 Georgia Chalkiadaki A1 Marina Vafeiadi A1 Manolis Kogevinas A1 Leda Chatzi YR 2021 UL http://jech.bmj.com/content/75/1/29.abstract AB Background Maternal thyroid hormones’ supply is crucial for fetal neurodevelopment; however, the role of maternal mild thyroid dysfunction is not clear. We aimed to assess the association of maternal mild thyroid dysfunction with child neuropsychological development from infancy to early childhood.Methods We included 757 mother–child pairs from the prospective ‘Rhea’ cohort on Crete, Greece. Maternal thyroid functioning was assessed by quantitative analysis of serum thyroid-stimulating hormone, free thyroxine, thyroid peroxidase antibodies and thyroglobulin antibodies at early gestation (mean=14 weeks). Neuropsychological assessment was based on Bayley Scales of Infant Development (18 months of age), McCarthy Scales of Children’s Abilities (4 years of age), Raven’s Coloured Progressive Matrices, Trail Making Test and Finger Tapping Test (6 years of age).Results In multivariate adjusted linear regression analyses, maternal hypothyroxinemia was associated with decreased verbal scores at 4 years and reduced motor speed at 6 years of age. Maternal thyroid autoimmunity was associated with decreased child perceptual and motor ability at 4 years of age. Four trajectories of longitudinal non-verbal cognitive development were identified and children exposed to maternal thyroid autoimmunity had increased risk for belonging to an adverse trajectory (‘low’: adjusted relative risk ratio (RRR) = 2.7 95% CI: (1.4, 5.2), ‘high-decreasing’: adjusted RRR = 2.2 95% CI: (1.2, 4.0), ‘low-increasing’: adjusted RRR = 1.8 95% CI: (1.0, 3.2)).Conclusion Maternal hypothyroxinemia is associated with reduced offspring verbal and motor ability. Maternal thyroid autoimmunity is associated with decreased offspring perceptual performance and motor ability and increased risk for adverse non-verbal cognitive development from infancy to childhood.