Retrospective analysis on prenatal screening of 38 639 pregnant women from 2009 to 2012

Objective: To explore the applications of serum free β-human chorionic gonadotropin( β-hCG) and alpha fetoprotein( AFP) detection during the second trimester of pregnancy. Methods: The clinical data of 38 639 pregnant women in Xiaoshan Hospital from October 2009 to September 2012 were analyzed retrospectively,the serum levels of AFP and free β- hCG were detected by semi- automatic time- resolved fluorescence immunoassay; wallac software was used to evaluate fetal risks of Down's syndrome( DS),Edward syndrome( ES) and neural tube defect( NTD); the result of prenatal diagnosis and pregnancy outcome were followed up and analyzed. Results: Among 38 639 pregnant women,33 559 pregnant women( 86. 85%) were followed up successfully,994 high risk pregnant women( 2.96%) were found,including 838 DS high risk pregnant women,18 ES high risk pregnant women and 118 NTD high risk pregnant women. A total of 44 pregnant women( 4. 43%) of high- risk abnormalities and 304 pregnant women of low- risk abnormalities were found by prenatal diagnosis and follow- up; the false negative rate was 0. 93%. Conclusion: Maternal serum free β- hCG and AFP detection during the second trimester of pregnancy combined with maternal age,body weight,gestational week and pregnant history are helpful to find high risk pregnant women,which can improve the detection rate of fetal abnormalities combining with prenatal diagnosis.