Increased nuchal translucency in euploid fetuses—what should we be telling the parents?

Abstract

Nuchal translucency (NT) measurement between 11 and 14 weeks' gestation is an undisputed marker for aneuploidies. When conventional karyotyping is normal, enlarged NT is a strong marker for adverse pregnancy outcome, associated with miscarriage, intrauterine death, congenital heart defects, and numerous other structural defects and genetic syndromes. The risk of adverse outcome is proportional to the degree of NT enlargement. Although the majority of structural anomalies are amenable to ultrasound detection, unspecified genetic syndromes involving developmental delay may only emerge after birth. Concern over these prenatally undetectable conditions is a heavy burden for parents. However, following detection of enlarged NT the majority of babies with normal detailed ultrasound examination and echocardiography will have an uneventful outcome with no increased risk for developmental delay when compared to the general population. Counseling should emphasize this to help parents restore hope in normal pregnancy outcome and infant development. Copyright © 2010 John Wiley & Sons, Ltd.

Evolução perinatal e pediátrica de crianças com translucência nucal aumentada e cariótipo normal

“…Essa diferença pode ser explicada pelos diferentes pontos de corte utilizados na classificação de TN aumentada e no fato de que neste estudo as pacientes que optaram pela pesquisa do cariótipo fetal apresentavam a TN em um valor mais elevado (média 5,5). Aproximadamente 4% das pacientes rastreadas para aneuploidias no primeiro trimestre apresentaram TN acima do P95, o que foi concordante com outros estudos 17,33 , porém discordante de Bilardo et al 29 , que encontraram 8,6% de TN acima desse percentil. Essa diferença poderia ser explicada pela média de idade mais elevada das pacientes nesse grupo.…”

“…Outros estudos confirmam achado 16,18,24,25,29 . Quanto à avaliação pós-natal, ela foi normal (nascidos vivos e bem) em 92,5%.…”

“…Alguns autores têm relacionado casos de TN aumentada com déficit no desenvolvimento neurológico pós-natal 16,27,28 , mas em uma revisão recente, os autores concluíram que em fetos com TN aumentada, cariótipo normal e exame ecográfico morfológico normal, o risco de déficit no desenvolvimento neurológico pós-natal não é superior ao da população geral 29 .…”

The ‘thousand-dollar genome’: an ethical exploration

“…This screening outcome must take into account a broad spectrum of potential sub microscopic chromosomal abnormalities that can lead to extremely severe conditions. 64 Here too, the objective is to provide the pregnant woman (and her partner) with the best possible information about potential foetal abnormalities, allowing a well-considered decision to be made about whether or not to continue the pregnancy. If the decision is made to carry the pregnancy to term, obstetric and perinatal care can be offered based on the outcomes of the diagnostic testing in order to provide the child with optimal support.…”

Practical approach to obtain the mid‐sagittal plane of the fetal face at 11–13 weeks' gestation by two‐dimensional ultrasound

“…Sonographic measurement of fetal nuchal translucency (NT) thickness at 11-13 weeks' gestation is the most important single marker for identification of fetuses at high risk of aneuploidies 1 , structural defects 2 and genetic syndromes 3 . Measurement of NT thickness should be performed on a mid-sagittal view of the fetal profile, which is defined by presence in the image of the tip of the nose and the rectangular-shaped palate anteriorly, the translucent diencephalon and the nuchal membrane posteriorly 4 .…”