First trimester combined screening for Down's Syndrome with NT, Free-βhCG and PAPP-A / 中华检验医学杂志

ABSTRACT

Objective To explore the sensitivity of using NT,combined with serum biochemical markers (Free-βhCG,PAPP-A) for Down's Syndrome screening in early stage of pregnancy.Methods Collect pregnant women aged 17-45 years old voluntary antenatal screening in our hospital from March 2009to October 2010,a total of 11882 cases.Serum Free-βhCG and PAPP-A were measured NT value was determined by ultrasound at 11-13w+64 of gestation.Calculating combined screening (NT,Free-βhCG,PAPP-A),and serum integrated screening (Free-beta hCG,PAPP-A) risk,respectively,using the risk calculation software for the same person.Results Early pregnancy screening was performed in 11 882patients,18 had a fetus with Down's syndrome,a rate of 0.15％.The detection rates of Down's syndrome in combined screening and serum integrated screening were 83.3％ and 72.2％ respectively.The specificities were 98.4％ and 97.3％ and detection efficiency were 7.18％,3.90％ respectively.Areas under the curve (AUCs) of fhst-trimester combined screening and serum integrated screening were 0.975 (95％ CI0.943,1.007),0.901 (95％ CI0.789,1.013) respectively.Conclusion In early stage of pregnancy,combined screening for Down's syndrome has higher sensitivity and specificity than serological screening,has higher detection rate in the same false-positive rate case,which can effectively reduce the pregnant women to receive invasive puncture.