increased nuchal translucency and pregnancy outcome

background: to study the outcome of cases with nuchal translucency (nt) ≥ 95th centile in the first trimester of pregnancy. methods: this cross sectional study was performed at iranian fetal medicine foundation (fmf) between january 2009 and december 2011. totally, 186 cases with nt≥ 95th centile who attended for the first trimester screening were studied. all cases with increased nt including those with normal karyotype were followed up with anomaly scan at 18-22 weeks and fetal echocardiography at 22-24 weeks. pregnancy outcome was extracted from delivery records and pediatrics notes and telephone interviews. results: of screened cases, 186 fetuses had an nt≥95th centile, of them 19.8% were abnormal karyotype, including 29 cases of trisomy 21, three of trisomy 18, two of trisomy 13, three of turner syndrome. 77.8% did not show any abnormalities on follow-up examinations. 4.6% of cases were found to have malformation antenatally and 4% cases postnatally. 11.4% women elected termination of pregnancy without further follow up. there were 4.6% fetal loss and  1.3% hydrops fetalis. conclusion: in this unselected population, the study showed one out of four fetuses with enlarged nt had an adverse pregnancy outcome (miscarriage, fetal loss, and fetal abnormalities), however the chance of having a normal child after exclusion of chromosomal abnormalities and adverse pregnancy outcome was 95%.