ABSTRACT
objectives To explore the clinical significance of the triple screening method and fetal sonographic markers in Down syndrome screening. Methods The retrospective study included maternal blood serum triple-marker screening per-formed in normal singleton pregnancies at 14+1 to 19+6 weeks and ultrasonography screening for fetal chromosomal trisomy at 18+1 to 23+6 weeks from 2010 to 2013. Results In 24 368 pregancies, Karyotype analysis reveal 35 Down syndromes, the incidence is 0.14%(35/24 368). 25/35 were pregnancies with an expected date of delivery lower than 35 years old and 10/35 were pregnan-cies with an expected date of delivery higher than 35 years old. In 1 215 pregnancies, second-trimester serum screening showed high risk (cutoff>1:380), 14 were confirmed as Down syndromes ( sensitivity 40%;specificity 95.06%). In 1 142 pregnant women showed ultrasonography abnormalities, of which 11 were found to have Down syndrome (sensitivity 60%;specificity 91.09%). In 112 pregnancies, second-trimester serum screening and ultrasonography showed high risk, 4 were conformed as Down syn-drome (sensitivity 11.43%;specificity 99.56). Conclusions The most effective method of screening for Down syndrome is by maternal serum biochemistry. Ultrasonography is important in screening fetal trisomy 21. combined screening methods can improve the detection rate of trisomy 21.