Increased nuchal translucency, normal karyotype and infant development

Objective To investigate whether chromosomally normal fetuses with a nuchal translucency (NT) ≥ 99th percentile (3.5 mm) in the first trimester have an increased risk of delayed development at 2 years of age. Methods The study included children of women from 10 Danish hospitals who had fetal NT either ≥ 99th percentile (Group 1) or < 95th percentile (Group 2) in the first trimester. The groups were matched by gender, gestational age at birth and maternal age. There were twice as many children in Group 2 as in Group 1. Follow-up was conducted at 2 years of age, infant development being assessed by the ‘Ages and Stages Questionnaire’. The cut-off value for delayed development was defined as the 5th percentile from the first 100 questionnaires from Group 2. Results In a 1-year period 202 of 33 266 fetuses (0.6%) had NT ≥ 3.5 mm. Of these, 99 (49.0%) were liveborn with normal karyotype and normal ultrasound findings during pregnancy. The response rate to the ASQ was 83.3% in Group 1 and 71.4% in Group 2. A low ASQ score was found in 1.3% (1/80) and 4.4% (6/137) in Groups 1 and 2, respectively (P = 0.265), but no difference was found in the mean ASQ score between the two groups (P = 0.160). Conclusion Fetuses with NT ≥ 99th percentile, normal karyotype and normal ultrasound findings during pregnancy had no increased risk of developmental delay at 2 years of age compared with fetuses with normal NT (< 95th percentile). Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.