Relationship Between High-risk Serum Screening For Down Syndrome And Adverse Pregnancy Outcomes

ObjectivesTo investigate the relationship between high-risk serum screening for Down Syndrome(DS) and the incidence of adverse pregnancy outcomes, and evaluating its predictive value for adverse pregnancy outcomes. Methods13472 pregnant women that underwent serum screening for DS during the first trimester and second trimester and chose childbirth at Fujian Provincial Maternal and Child Health Care Hospital were investigated from January 1st to December 31 st of 2011. 807 cases whose value of serum screening for DS was > or = 1:270 were identified as high-risk group. There were 148 pregnant women with advanced maternal age(AMA) in the high-risk group. 1614 cases whose value of serum screening for DS was < 1:270 were identified as low-risk group, and there were 267 pregnant women with AMA. All cases were received genetic sonography at 18-24 gestational weeks. Fetal chromosomal diseases, genetic sonography, birth defects, pregnancy complications, perinatal outcomes of pregnant women were compared between the high-risk group and the low-risk group. And the result of serum screening and prenatal diagnosis were analyzed in pregnant women with AMA. Results1. In the high-risk group, 489 cases accepted prenatal diagnosis, the percentage of fetal chromosomal abnormalities was 3.89%(19 in 489), there were 9 cases with DS, 4 cases with sex chromosomal abnormalities and 6 cases with chromosomal inversion; 318 cases didn’t accept prenatal diagnosis, and among them there were 2 cases with DS, which were discovered during the follow-up after birth. In the low-risk group, there were 1 case with DS and 1 case with trisomy 13. The incidence rate of DS in the high-risk group 1.36%(11 in 807) was higher than that in the low-risk group 0.06%(1 in 1614)(P<0.001). The detection rate of DS was 91.67%(11 in 12).2. The incidence of sonographically structural abnormality in the high-risk group 5.82%(47 in 807) was higher than that in the low-risk group 1.80%(29 in 1614)(P<0.001).In the high-risk group, there were 47 cases with sonographically structural abnormalities among which 32 cases accepted prenatal diagnosis. The percentage of fetal chromosomal abnormalities was 21.88%(7 in 32). In the high-risk cases combined with fetal congenital heart disease(CHD), the percentage of fetal chromosomal abnormalities was 46.15%(6 in 13). However the percentage of fetal chromosomal abnormalities in the high-risk cases combined with other fetal structural abnormalities was 5.26%(1 in 19), which was lower than that with fetal CHD(P=0.021). In the high-risk cases combined with multiple fetal structural abnormalities, the percentage of fetal chromosomal abnormalities was significantly higher than that with single fetal structural abnormality(75% vs 14.29%, respectively, P=0.025).3. The incidence of birth defects in the high-risk group was higher than that in the low-risk group(9.05% vs 3.90%, respectively, P<0.001). In the high-risk group, 59 cases(80.82%) of 73 cases with birth defects were diagnosed before birth. The main birth defect was fetal CHD following with chromosome abnormalities.4. In the high-risk group, the incidence of abortion, fetal death, placental abruption and neonatal asphyxia was 4.09%(33 in 807), 2.11%(17 in 807), 1.12%(9 in 807) and 1.36%(11 in 807) respectively, which were all higher than that in the low-risk group, 0.12%(2 in 1614), 0.31%(5 in 1614), 0.31%(5 in 1614) and 0.25%(4 in 1614) respectively(P<0.05).5. In the high-risk group, 91 cases of 148 women with AMA accepted prenatal diagnosis; the percentage of fetal chromosome abnormalities was 7.69%(7 in 91). Meanwhile in the low-risk group, 64 cases of 267 women with AMA accepted prenatal diagnosis, and abnormal chromosomal karyotype was not found. In the women with AMA, the incidence rate of fetal chromosome abnormalities in high-risk group was significantly higher than that in low-risk group(P=0.022). Conclusions1. DS could be detected by high-risk serum screening combined with prenatal diagnosis, with the detection rate of 91.67%, as well as other chromosomal abnormalities, such as sex chromosomal abnormalities and chromosomal inversion.2. The incidence of sonographically fetal structural abnormalities was high in the cases with high-risk serum screening for DS. In the high-risk cases with sonographically fetal structural abnormalities, the percentage of fetal chromosome abnormalities was increasingly high. Moreover, in the high-risk cases combined with sonographically fetal structural abnormalities, such as CHD and multiple structural abnormalities(especially CHD and other structural abnormalities), the risk of aneuploidy was significantly increased.3. Among the cases with high-risk serum screening for DS, the incidence of adverse pregnancy outcomes such as birth defects, abortion, fetal death, placental abruption, and neonatal asphyxia was high.4. Maternal serum screening tests could be applied in pregnant women with AMA.