Chew S, Anandakumar C, Ratnam S S
Department Obstetrics and Gynaecology, National University Hospital, Singapore.
Singapore Med J. 1995 Aug;36(4):417-23.
Down's syndrome is the most common chromosomal abnormality whose incidence increases with advancing maternal age. However, approximately 70% of all Down's syndrome foetuses occur in mothers aged less than 35. Maternal serum markers have been used in an attempt to identify Down's syndrome pregnancies in these low risk mothers. Numerous second trimester maternal serum markers have been documented in the literature and these are reviewed. The Triple test which uses second trimester maternal serum levels of alpha-feto protein, human chorionic gonadotrophin and unconjugated oestriol is the most popular combination in use today. Although it is associated with a 58% detection rate for Down's syndrome pregnancies at a false positive rate of 5%, the Triple test has its problems and these are discussed. The cost-effectiveness of Down's syndrome screening using the Triple test and its role in mothers aged 35 years or more are also explored. Several workers have reported on first trimester serum markers of foetal Down's syndrome but more data is needed before a first trimester serum screening programme for Down's syndrome is possible.
唐氏综合征是最常见的染色体异常疾病，其发病率随母亲年龄增长而增加。然而，所有唐氏综合征胎儿中约70%发生在年龄小于35岁的母亲身上。母体血清标志物已被用于尝试在这些低风险母亲中识别出怀有唐氏综合征胎儿的妊娠情况。文献中已记录了许多孕中期母体血清标志物，本文将对这些标志物进行综述。三联筛查法使用孕中期母体血清中的甲胎蛋白、人绒毛膜促性腺激素和非结合雌三醇水平，是目前使用最广泛的组合方法。尽管该方法在唐氏综合征妊娠检测率为58%时假阳性率为5%，但三联筛查法仍存在问题，本文将对此进行讨论。还探讨了使用三联筛查法进行唐氏综合征筛查的成本效益及其在35岁及以上母亲中的作用。一些研究人员报告了孕早期胎儿唐氏综合征的血清标志物，但在开展孕早期唐氏综合征血清筛查项目之前，还需要更多数据。
