| Combined with cytogenetic examination, the prenatal screening strategy of the pregnancy women in second-trimester analyzed the concentration of maternal serum markers including a-fetoprotein (AFP), free β-human chorionic gonadotropin (free β-hCG) and unconjugated oestriol (uE3) to forecast the potential chromosome defects in fetus economically, which is more quickly and simply with lower false-positive rate. There were numerous serum screening data in China, which showing different geographical characteristics. Some developed provinces in China have set up local database for prenatal screening. Due to the low economic condition, the prenatal screening in Yunnan Province started late, and there were less systemic studies about prenatal screening strategy in Yunnan Province. Therefore, it is necessary to analyze the local maternal serum screening data to elevate the current prenatal screening strategy so as to establish a prenatal serum screening strategy to fit the pregnancy women in Yunnan Province, which finally contribute to improve detection rate.The concentrations of AFP, free β-hCG and uE3 from 11,201 singleton samples and 157 twin pregnancies were measured by time-resolved fluoroinnumoassay (Triple test). The concentrations of maternal serum markers inh A, AFP, free β-hCG and uE3 from 2,062 singleton samples were measured by time-resolved fluoroinnumoassay (Quadruple test), and the karyotype of fetus has been confirmed by cytogenetic examination; finally the data was analyzed using Excel and SPSS 19.0 to compare the difference between different screening strategy. The results showed that:① the detection rate of fetus defects was 82.35 when the false positive rate was 4.13%. The sensitivity and specificity were 82.35% and 95.87% respectively. The Youden index was 78.22%. The positive likelihood ratio was 19.95. The negative likelihood was 0.18. The positive predict value was 5.73%. The negative predict value was 99.94%. The ROC curve dimension was 0.979.② the pregnancy women in current prenatal screening were divided into two groups according to their age. Compared the results of these two groups, the results of clinical trail assessment in the pregnancy women who were younger than 35 were better than that in the pregnancy women who were 35 years old or above. The ROC curve dimension was 0.985 in pregnancy women who are younger than 35, while it was 0.92 in pregnancy women who are 35 years old or above. The costs to determine each fetus with abnormal karyotype in pregnancy women who are older than 35 was double of which in another age group.③ the concentration of serum markers a-fetoprotein and unconjugated oestriol increased with the gestational weeks. The concentration of human chorionic gonadotropin declined with a wave-shaped oscillation from 15 to 21 gestational weeks. After statistical analysis, significant difference was not found between the levels of serum marker a-fetoprotein in twin and singleton pregnancies in 15gestational week (P>0.05), but there was significant difference in 16 to 21 gestational weeks (P<0.05). While considering free β-hCG, significant differences were not found in 15 and 21 gestational weeks (P>0.05), but the significant differences were found from 16 to 20 gestational weeks (P<0.05). There were significant differences between the levels of unconjugated oestriol in twin and singleton pregnancies in all gestational weeks (P<0.05).④ there were different concentrations of maternal serum markers between twin and singleton pregnancies. The estimated risk of chromosome aberration in twin pregnancies cannot be calculated based on the theory that maternal serum concentration of markers in singletons. It was interesting that the concentration of a-fetoprotein in twins pregnancies was close to twice of the singletons.⑤ the concentration of maternal serum marker inh A decreased from 15 to 17 gestational weeks, and reached the lowest point in 17 gestational week. The concentration of inh A increased slowly in 18 gestational week, and reached a higher point in 21 gestational week. The median curve of inh A concentration was u-shaped.⑥ the relationship among gestational weeks, age and weight were analyzed. The significant differences of inh A concentration were not found in 15 and 16 gestational weeks. The same result was showed in 20,21 gestational weeks and other gestational weeks. There was no relationship between the inh A concentration and the age of pregnancy women (P>0.05). There was relationship between the inh A concentration and the weight of pregnancy women (P<0.05).⑦ there was relationship among four serum markers by comparing the concentration of them (P<0.05).⑧ the result of clinical trail assessment in quadruple test was lower than that in triple test. The ROC curve dimension was 0.964 in quadruple test, while it was 0.979 in triple test.The significance of this study was:based on the triple test and quadruple test data from pregnancy women, it was the first time to assess prenatal screening strategy in Yunnan Province systemically, and it would bring comments to improve this proposal. Firstly, it is not necessary to do cytogenetic examination in the senile pregnancy women. Secondly, the concentration of maternal serum marker AFP in twins pregnancies was close to twice of that in singleton pregnancy, and the level of AFP can be used in calculating the estimated risk of chromosome aberration in twin pregnancies. Finally, triple test proposal is better for singleton pregnancy women in Yunnan Province. Our study provide scientific basis for choosing prenatal screening strategy in Yunnan Province. |
PDF Full Text Request