Qi Qing-Wei, Jiang Yu-Lin, Liu Jun-Tao, Bian Xu-Ming, Li Yan, Lü Shi-Ming, Zhu Bao-Sheng, Wang He, Xu Zheng-Feng, Pan Xiao-Ying, Cai Yan
Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China.
Zhonghua Fu Chan Ke Za Zhi. 2008 Oct;43(10):737-41.
To evaluate the performance characteristics of the second trimester double test for the detection of fetal Down's syndrome (DS) in women of advanced maternal age (AMA).
We undertook a prospective nation-wide multi-centered study and chose alpha-fetoprotein (AFP) and free beta-subunit of human chorionic gonadotrophin (free beta-hCG) as the serum markers. Between May 2004 and September 2006, 12 centers participated in the collection and analysis of maternal serum AFP and free beta-hCG. Patients with an increased risk of DS (> or = 1/270) were offered genetic amniocentesis. Follow up of the outcome of all pregnancies was obtained. Patients were divided into two groups, the AMA group and the non-AMA group and the screening efficiency was evaluated in both groups.
A total of 66 132 singleton pregnancies were included in the study, and there were 3610 (5.46%) AMA women. The median maternal age of AMA women was 36.8years (35 - 47 years). At a cut-off of 1/270, in the AMA group, the number of positive cases screened was 727 and 22 cases of fetal DS were detected; the number of negative cases screened was 2883, and no fetal DS was found. In the non-AMA group, the number of positive cases screened was 4743 and 69 cases of fetal DS were detected; the number of negative cases screened was 57 779, and 6 cases of fetal DS were diagnosed postnatally. In AMA group, the detection rate (DR), false positive rate (FPR) and odds of being affected given a positive result (OAPR) were 100%, 19.7% and 3.0% respectively. In the non-AMA group, the DR, FPR and OAPR were 92.0%, 7.5% and 1.5% respectively.
The double-marker test using AFP and free beta-hCG is an effective screen strategy for second-trimester detection of Down syndrome in AMA women.
评估孕中期二联检测法在高龄孕产妇中检测胎儿唐氏综合征（DS）的性能特征。
我们开展了一项全国性的前瞻性多中心研究，选择甲胎蛋白（AFP）和人绒毛膜促性腺激素游离β亚基（游离β-hCG）作为血清标志物。2004年5月至2006年9月期间，12个中心参与了孕产妇血清AFP和游离β-hCG的收集与分析。对DS风险增加（≥1/270）的患者进行了遗传羊膜腔穿刺术。获取了所有妊娠结局的随访信息。将患者分为两组，即高龄孕产妇组和非高龄孕产妇组，并对两组的筛查效率进行了评估。
该研究共纳入66132例单胎妊娠，其中高龄孕产妇3610例（5.46%）。高龄孕产妇的中位年龄为36.8岁（35 - 47岁）。在截断值为1/270时，高龄孕产妇组筛查出阳性病例727例，检测出胎儿DS 22例；筛查出阴性病例2883例，未发现胎儿DS。非高龄孕产妇组筛查出阳性病例4743例，检测出胎儿DS 69例；筛查出阴性病例57779例，产后诊断出胎儿DS 6例。在高龄孕产妇组中，检测率（DR）、假阳性率（FPR）和阳性结果时患病几率（OAPR）分别为100%、19.7%和3.0%。在非高龄孕产妇组中，DR、FPR和OAPR分别为92.0%、7.5%和1.5%。
使用AFP和游离β-hCG的二联检测法是孕中期检测高龄孕产妇唐氏综合征的有效筛查策略。
