Pregnancy outcome and prognosis in fetuses with increased first-trimester nuchal translucency

Objective: One of the concerns of prenatal diagnosis is to find sensitive m arkers to screen for chromosome abnormalities, such as serum assays or nuch al translucency (NT). This study reports our experience with NT measurement during the first trimester of pregnancy. Materials: The study was performe d prospectively on 252 fetuses with either NT greater than or equal to3 mm or cystic hygroma. Results: We observed 50 abnormal karyotypes, i.e. 19.8%. The incidence of chromosome abnormalities increased with increasing matern al age and increasing NT thickness. For the 202 fetuses with normal karyoty pes, outcome was unfavourable in 32 cases: 23 elective terminations of preg nancy, 8 spontaneous abortions and I neonatal death. Outcome was favourable in 141 cases. Twenty-nine pregnancies were lost to follow-up. Conclusion: Measurement of NT at 12 weeks' gestation seems to be a good marker for chro mosome abnormalities. When the karyotype is normal, the pregnancy outcome r emains correlated with the degree of NT thickness. The finding of NT >3 mm between 10 and 14 weeks' gestation dictates rigorous ultrasound monitoring and caution when predicting pregnancy outcome. Copyrlight (C) 2001 S. Karge r AG, Basel.