Impact of Increased Nuchal Translucency Values on Pregnancy Outcomes: A Tertiary Center Experience.

Objective: We evaluated the association of nuchal translucency (NT) values above 99th percentile with perinatal outcomes. Materials and methods: Singleton pregnancies with NT values above 99th percentile were investigated. Pregnancies were divided into 3 groups: group 1, NT = 2.6-<3.5 mm; group 2, NT = 3.5-4.5 mm; and group 3, NT > 4.5 mm. Demographic features, clinical characteristics, structural/chromosomal anomaly rates and perinatal outcomes were compared. Results: Normal ultrasonographic anatomy was found in 47.5%, 7.7%, and 14.3% of groups 1, 2, and 3, respectively ( p  = 0.006). Group 3 had the lowest normal karyotype rate (44.6%) ( p  = 0.005). Higher frequencies for both miscarriage and pregnancy termination were observed in group 3 compared to group 1 (8.9% vs. 4.9% and 66.1% vs. 32.7%, respectively) ( p  = 0.02). The lowest rate of normal postnatal anatomic findings was found in group 3 (10.7%) ( p  = 0.01). Conclusion: NT values above 99th percentile for gestational age seem to be associated with increased rates of chromosomal/structural abnormalities and adverse perinatal outcomes.