Analysis of prenatal screening chromosomal abnomality syndrome in first and second trimester

Objective:Toinvestigate the effectiveness of prenatal screening in First and second trimester.Methods: Serum(PAPP-A and free-β-hCG) level of 4297 pregnant women in First trimester and Serum(free-β-hCG and AFP and uE3) level of 28490 pregnant women in second trimester were detected.The risk value was calculated with Lifecycle 3.0 software.The pregnant women who were in high risk need to receive fetal karyotype analysis.Results: In First trimester underwent prenatal screening,157 of them were in high risk,3 cases of Down′s syndrome were determined,while in second trimester underwent prenatal screening,1978 of them were in high risk,15 cases of Down′s syndrome,8 cases of trisome18 and one case of trisome13 were determined.There was significant difference in the false positive rate in the two groups(First trimester and second trimester groups)(3.34% and 6.74%,P0.01).Conclusion: The prenatal screening in first second trimester is superior to in second trimester.The amount of unnecessary fetal karyotype analysis reduced remarkably because of the prenatal screening in first second trimester,which can avoid unnecessary fetal loss.