Comparison of effectiveness of maternal serological screening and age screening among the pregnant women of advanced maternal age for fetal Down's syndrome

Objective: To compare effectiveness of maternal serological screening and age screening among the pregnant women of advanced maternal age for fetal Down's syndrome,find an effective and economical screening regimen. Methods: Serological screening was performed among the pregnant women of advanced maternal age in the hospital from 2011 to 2012. Prenatal diagnosis was conducted among the high risk women; pregnancy outcome of all the pregnant women was followed up; positive predictive value and detection rate of Down's syndrome were calculated; the pregnant women receiving prenatal diagnosis with advanced maternal age as the only indication were selected as control group. Results: A total of 3 714 women of single pregnancy received serological screening,688 women( 18. 52%) were found as high risk women,228 women( 33. 14%) underwent amniocentesis,10 women were diagnosed as Down's syndrome,the positive predictive value was 4. 39%( 10 /228),the low risk women were followed up,no neonate was found with Down 's syndrome,the detection rate of Down's syndrome was 100. 00%. A total of 216 women in control group received prenatal diagnosis,no neonate was found with Down's syndrome,only two neonates were found with chromosomal structural abnormality. There was statistically significant difference in positive predictive value of Down's syndrome between the two groups( P 0. 05). A total of 3 026 women were found as low risk women by serological screening,15 women received prenatal diagnosis,three neonates were found with sex- linked chromosomal abnormalities( trisomic syndrome),one neonate was found with trisomy 13,one neonate was found with chromosomal structural abnormality,the morbidity of chromosomal abnormalities was 0. 17%( 5 /3 026). The rate of amniocentesis among the women with positive serological screening result was higher than that in control group by 81. 07%,and the cost for prenatal diagnosis was saved by 69. 68%. The follow- up rates of pregnancy outcome among high risk women and low risk women were 84. 01% and 82. 78%,respectively; the rates of adverse reactions among high risk women and low risk women were 11. 59%( 67 women) and 7. 15%( 179 women),there was statistically significant difference between the two groups( χ2= 12. 64,P 0. 05). Conclusion: The effectiveness of maternal serological screening is obviously better than that of single age screening among the pregnant women of advanced maternal age for fetal Down's syndrome,maternal serological screening can effectively reduce the rate of invasive prenatal diagnosis and dominantly save cost for prenatal diagnosis,which is a high- effective and economical screening regimen,it is recommended to replace age screening with maternal serological screening.