RESUMO
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 ß-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. RESULTS: of 3,610 single fetuses included in the study, we had a complete follow-up on 2,984. Fourteen of 17 cases of trisomy 21 were detected when a cut-off of 1:300 was applied [detection rate (DR) 82.4%, 95% confidence interval (CI) 64.2-100; false-positive rate (FPR) 4.7%, 95% CI 3.9-5.4; false-negative rate (FNR) 17.6%, 95% CI 0-35.8%]. CONCLUSION: in our study population the detection rate for trisomy 21, using the combined risk calculation based on maternal age, fetal NT, maternal PAPP-A and free ß-hCG levels, was superior to the application of either parameter alone. The algorithm has been validated for first trimester screening in the Italian population.
RESUMO
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. The fetal standard biometric measurements were recorded. For each parameter, regression models were fitted to estimate the percentile at each gestational age. In order to be compared to other reference equations, the fetal biometric measurements at each gestational age were expressed as Z-scores. RESULTS: New fetal charts and references equations for Italian population were developed according to the recommend multistep statistical procedure. CONCLUSION: To our knowledge this is the first Italian study with the largest sample size ever reported in the literature. In addiction, our newer charts of reference centiles for fetal biometric measurements are useful in the obstetrical clinical practice for the Italian population.
