Neurodevelopmental outcome at 2 years of corrected age for fetuses with increased nuchal translucency and normal karyotype compared to matched controls

OBJECTIVES: Increased nuchal translucency (NT) is an antenatal marker of aneuploidy or malformation that frequently leads to pregnancy termination. This study assessed the long-term prognosis of infants with isolated, increased NT. METHODS: We prospectively followed 490 infants with an NT thickness above the 95th percentile during the first trimester, but with a normal karyotype and no major anomalies. At 2 years of corrected age, they were compared to controls matched for birthweight, Apgar score, birthplace, mothers' parity and gestational age. Their developmental quotient (DQ), postural, language, coordination, sociability and global scores were assessed by the Brunet-Lezine test. RESULTS: Results were available for 203 infants in the increased NT group and 208 in the control group (84%). The mean DQ was significantly lower in the NT group than in the controls (108.6 +/-9.7 versus 112.8 +/-8.3) (p <0.0001), but within the normal range. Only one case had a DQ below 70. The results remained significant for an NT threshold above the 99(th) percentile and when the data were adjusted for NT thickness, sex and mothers' education. Over half (56%) had an NT of up to 3.5mm, 33% were between 3.5mm-5mm and 11% were over 5mm, with a mean DQ of 108.4, 110.1 and 109.7, respectively. CONCLUSION: Infants with prenatal and isolated increased NT, in the first trimester, had a significantly lower, but normal, developmental quotient at a corrected age of 2 years, when compared to the controls. The findings were independent of sex, NT thickness and mothers' education. This article is protected by copyright. All rights reserved.