Association between unexplained thickened nuchal translucency and adverse pregnancy outcomes

To determine the association between unexplained increased nuchal translucency (INT) and adverse pregnancy outcomes. The prospective database of our fetal down screening project was accessed to retrieve the records with NT measurement and complete follow-up. Pregnancies with pre-existing medical diseases, fetal chromosomal or structural abnormalities were excluded. The selected pregnancies were classified into the INT groups (> 95th percentile), the normal (< 95th percentile) group. Of 6026 available for analysis (INT:277; and normal: 5749), the abortion rate was significantly higher in the INT group, 18/277 (6.5%) versus 55/5749 (1.0%); p < 0.001. After excluding 73 cases ending-up with abortion, a total of 5953 women were analyzed for final pregnancy outcomes, including 260 (4.4%), and 5693 (95.6%) in the study group (INT), and the control group (normal NT), respectively. The rates of pre-eclampsia (7.3 vs. 4.1%; p: 0.018), preterm birth (12.7 vs. 8.4%; p: 0.023), fetal growth restriction (11.5 vs. 7.6%; p: 0.032), and low birth weight (16.5 vs. 10.0%; p: 0.002) were slightly, but significantly higher in the study group. INT in the first trimester is associated with significantly increased risk of abortion, fetal growth restriction, preterm birth, low birth weight and pre-eclampsia.