AbstractBackground Thickened nuchal translucency (NT) has been related to fetal genetic syndromes, structural abnormalities, and other diseases. The aim of this research was to evaluate the association of NT with adverse pregnancy outcomes. Study design In the period 2002–2004 in 2104 pregnant women between 10 + 6 and 13 + 5 weeks' gestation, NT was evaluated as a parameter for aneuploidy screening: out of these, 734 singleton pregnant women that underwent 2nd trimester amniocentesis and whose pregnancy outcome were known were selected. NT was statistically correlated to pregnancy and neonatal outcome. Results Median gestational age (GA) at NT evaluation was 11 + 2 weeks' gestation. NT median was 1.1 mm (0.9–1.4 mm, 25th–75th centile, range 0.5–4.0 mm). After multiple logistic regressions, the variables significantly associated to NT values were: threatened preterm labor (p < 0.008) and preterm labor (p < 0.02). The best diagnostic accuracy point was NT > 95th centile and > 1.5 MoM for the prediction of threatened preterm labor. Conclusion In this series, increased NT values were associated to threatened preterm labor and preterm labor in euploid fetuses: this finding may have clinical consequences in the management of such pregnancies.