Elevated nuchal translucency, is it time to discuss the cut off?. A
retrospective study
Abstract
Objectives To evaluate pregnancy and postnatal outcomes of fetuses with
NT between 95th and 99th percentile and whether they could benefit from
further investigations rather that routine scans. Design Retrospective
multicenter observational study. Setting Two Italian Fetal Medicine
centre Population All cases with NT between 95th and 99th percentile
(667) among women undergoing NT measurement between January 2015 and
December 2020. Methods Unfavourable outcome was considered as:
miscarriage or intrauterine fetal death (IUFD), chromosomal
abnormality/genetic syndrome, major malformation or neurodevelopmental
delay. Study population outcomes were compared with general population.
Main Outcome Measures Unfavourable pregnancy and postnatal outcomes.
Results The rate of unfavourable outcome was 25.44%. We reported: 6
(0.90%) second trimester miscarriage or IUFD, 90 (13.49%) chromosomal
abnormalities/genetic syndromes, 57 (8.55%) major malformations, 13
(1.95%) cases of neurodevelopmental delay. The incidence of chromosomal
abnormalities/genetic syndromes and major malformations were
significantly higher (OR 6.99 (IC 95% 4.33 - 11.28), p<0.001
and OR 17.77 (IC 95%7.22 - 43.75), p<0.001 respectively)
compared to the general population. The incidence of neurodevelopmental
delay was not increased (OR of 0.64 CI 95% 0.33 - 1.24 p=0.185).
Conclusions Fetuses with NT between 95th and 99th percentile have an
increased risk of pregnancy and postnatal adverse outcomes. According to
our data it is reasonable to consider a lower NT cut off
(NT>95th percentile) for offering further investigations
such as detailed ultrasound scan, fetal echocardiography and counselling
where the option of performing fetal karyotype and CGH array should be
discussed. Funding The authors have no funding to declare.