ObjectiveTo analyze the prenatal screening data of Longquanyi district, and evaluate the effect of prenatal screening technology in birth defects prevention. MethodsA total of 10230 serum samples in Chengdu Longquanyi District Prenatal Screening Center from November 2010 to December 2012 were tested and analyzed, and the risk rates of Down's Syndrome, Trisomy 18 Syndrome and Open Neural Tube Defects (ONTDs) were obtained by Risk2T risk calculation software. The results of prenatal screening were verified and evaluated by high risk referral, pregnancy tracing and pregnancy outcome follow-up. ResultsIn the 10 230 pregnant women, the positive rate of Down's Syndrome was 6.02%, Trisomy 18 Syndrome was 0.42% and Open Neural Tube Defects was 0.57%, and compliance rate of prenatal diagnosis was 51.56%. In the 57 high risk pregnant women of ONTDs, 53 women selected system color doppler ultrasound with a proportion of 92.98%, but in the 647 high risk pregnant women of Down's or Trisomy 18 Syndrome, only 47.30% of them chose amniocentesis for diagnosis. The χ2 analysis showed that the difference was significant compared between system color doppler ultrasound and amniocentesis group (P<0.05). By diagnosis, 3 Down's Syndrome patients were found. ConclusionSecond trimester maternal serum prenatal screening plays an important role in birth defects prevention in Longquanyi district. However, there is a great need to improve compliance rate of prenatal diagnosis of Down's and Trisomy 18 Syndrome.