Retrospective study evaluating the performance of a first-trimester combined screening for trisomy 21 in an Italian unselected population.

Objectives: to assess the performance of a combined first-trimester screening for trisomy 21 in an unselected Italian population referred to a specialized private center for prenatal medicine.

Methods: a retrospective validation of first-trimester screening algorithms [risk calculation based on maternal age and nuchal translucency (NT) alone, maternal age and serum parameters (free β-hCG and PAPP-A) alone and a combination of both] for fetal aneuploidies evaluated in an unselected Italian population at Artemisia Fetal-Maternal Medical Centre in Rome. All measurements were performed between 11(+0) and 13(+6) weeks of gestation, between April 2007 and December 2008.

Reference interval for fetal biometry in Italian population.

Objectives: To validate new references charts and equations for fetal biometry in an Italian unselected population.

Methods: A cross-sectional study involving 4896 women with singleton viable pregnancies, at Artemisia Fetal Maternal Medical Centre between May 2009 and December 2009. Each woman was scanned only once, between 14+0 and 40+0 weeks of gestation.