Increased nuchal translucency thickness and risk of neurodevelopmental disorders

Objective To investigate the association between fetal nuchal translucency (NT) thickness and neurodevelopmental disorders in euploid children. Methods This study included 222 505 euploid children who had undergone routine first-trimester screening during fetal life. Children were divided according to prenatal NT into three groups: NT < 95th percentile (n=217 103 (97.6%)); NT 95th-99th percentile (n=4760 (2.1%)); and NT > 99th percentile (n=642 (0.3%)). All children were followed-up to a mean age of 4.4 years. Information on diagnoses of intellectual disability, autism spectrum disorders (ASD), cerebral palsy, epilepsy and febrile seizures was obtained from national patient registries. Results There was no excess risk of neurodevelopmental disorders among euploid children with first-trimester NT 95th-99th percentile. For children with NT > 99th percentile, there were increased risks of intellectual disability (odds ratio (OR), 6.16 (95% CI, 1.51-25.0), 0.31%) and ASD (OR, 2.48 (95% CI, 1.02-5.99), 0.78%) compared with children with NT < 95th percentile (incidence of 0.05% for intellectual disability and 0.32% for ASD), however, there was no detected increase in the risk of cerebral palsy (OR, 1.91 (95% CI, 0.61-5.95), 0.47%), epilepsy (OR, 1.51 (95% CI, 0.63-3.66), 0.78%) or febrile seizures (OR, 0.72 (95% CI, 0.44-1.16), 2.65%). Conclusions In a large unselected cohort of euploid children, there was no increased risk of neurodevelopmental disorders among those with a first-trimester NT 95th-99th percentile. Among euploid children with first-trimester NT > 99th percentile, there were increased risks of intellectual disability and ASD, but the absolute risk was reassuringly low (< 1%). Copyright (C) 2017 ISUOG. Published by John Wiley & Sons Ltd.