Long-term outcome in apparently healthy children with increased nuchal translucency in the first trimester screening

Introduction: Increased nuchal translucency is known to be associated with chromosomal and structural defects and genetic syndromes. Little is known about the overall long-term outcome of euploid children after increased nuchal translucency. The aims of this study were to assess the additional structural defects diagnosed after discharge from the delivery hospital and the long-term overall outcome of euploid children after increased nuchal translucency and normal second trimester anomaly scan.

Material and methods: All children from singleton euploid pregnancies during 2002-2007 with increased nuchal translucency in the first trimester screening, normal second trimester anomaly scan, and discharged as apparently healthy were included. Data on the structural defects and genetic disorders diagnosed until 2012 were retrieved from hospital databases and national registers. Previously published data of structural defects diagnosed after birth but before discharge and of severe neurodevelopmental impairment and genetic syndromes was added.

Results: The cohort included 733 children. During the follow-up time (mean 6.5 years), major structural defects were observed in 10 (1.4%), genetic disorders in two (0.3%), and minor defects in 23 (3.1%) children. In addition, there were 42 previously published major structural defects and major neurodevelopmental impairment or genetic disorders. Adding these results together, major health problems were detected in 54 (7%) euploid children with increased fetal nuchal translucency and normal findings in second trimester anomaly scan.

Conclusion: Although only few additional major structural defects are diagnosed during the follow-up after increased fetal nuchal translucency, 7% of fetuses assumed to be healthy after second trimester anomaly scan have a major health impairment.