Objective To evaluate the association between abnormal ductus venosus (DV) at 11-14 weeks' gestation and chromosomal abnormalities, structural defects and fetal outcome. 2%, 96.9%, 31.3% and 99.3%, respectively, 97.6%, 36.6% and 99.3%, respectively, when Methods DV flow-velocity waveform (DV-FVW) and nuchal translucency thickness (NT) were prospectively evaluated in 1217 singleton pregnancies. Results

Objective:The aim of this study was to evaluate prenatal and postnatal outcomes of fetuses with increased nuchal translucency thickness (NT) and normal karyotype. MethOds: Two hundred seventy-five fetuses with increased NT were submitted to karyotyping analysis, serial ultrasound scans, echocardiography and postnatal clinical and genetic evaluation at the Division of Fetal Medicine of the Obstetric Outpatient Clinic of Universidade de São Paulo. Results:The karyotype was abnormal in 14.2% of the cases and normal in 85.8%. In cases with normal karyotype, 24.7% presented structural abnormalities in the second-trimester ultrasound scan, and one third showed major malformations, 35.7% of which consisted of heart defects. Adverse pregnancy outcome such as miscarriages, intrauterine and neonatal deaths occurred in 10.2% of cases. Postnatal follow-up was established for 72.7% of infants, and abnormalities were observed in 14.8% of them. Chances of having a live and healthy infant decreased with increased NT thickness, corresponding to 37.5% for NT equal to or greater than 4.5 mm. cOnclusiOn: In cases with increased NT thickness and normal karyotype, the frequency of fetal malformations, especially heart defects, adverse pregnancy outcomes and postnatal abnormalities is related to NT thickness.

Increased NT measurement at 11 to 13 weeks and 6 days is an important marker for fetal chromosomal and structural abnormalities, mainly fetal cardiac defects. This finding also indicates increased risk of spontaneous fetal and neonatal death.