Pregnancy outcome in fetuses with increased nuchal translucency

Abstract

Objective: The aim of this study was to examine fetal and neonatal outcomes in the setting of nuchal translucency (NT) > or =3 mm at routine first-trimester screening.

Study design: A nested case-series study within a retrospective cohort of women screened for Down syndrome at 11-14 weeks of gestation. Crown-rump length, NT values and additional anomalies at first and early second trimesters were recorded. Follow-up information was obtained by a review of medical records and self-report from patients. Adverse outcomes included fetal death and termination of pregnancy due to structural or chromosomal anomalies.

Result: A total of 1930 pregnant women were screened between 11 and 14 weeks of gestation. The prevalence of increased fetal NT (> or =3 mm) was 1.4% (n=27). Among these, 12 showed increased fetal NT as an isolated finding. In this group, 2 women experienced fetal demise (16%) and 10 delivered healthy babies. In the group with additional abnormalities (n=15), 9 (60%) were found to have chromosomal abnormalities, all of which were terminated. For all cases with increased fetal NT, total incidence of adverse outcome was 62%.

Conclusion: At first-trimester ultrasonography, a fetal NT > or =3 mm was associated with a high incidence of chromosomal abnormalities in the presence of associated abnormalities. For cases with the increased fetal NT at first-trimester fetal assessment and follow-up is necessary to detect possible adverse outcomes.