Jou Hei-Jen, Kuo Yih-Shing, Hsu Jenn-Jeih, Shyu Ming-Kwang, Hsieh T'sang-T'ang, Hsieh Fon-Jou
Department of Obstetrics and Gynecology, Taiwan Adventist Hospital, Taipei, Taiwan.
Prenat Diagn. 2005 Aug;25(8):665-70. doi: 10.1002/pd.1220.
The aim of the present study was to determine whether the liberal use of second-trimester maternal serum screening in Taiwan started in 1994 had a measurable impact on birth prevalence of infants with Down syndrome (DS) in the past decade.
We based our study on the databases of 'National Birth Defect Registration and Notification System', 'Amniocentesis in Pregnant Women', and 'Demographic Fact Book' in Taiwan. Collected data included total registered birth number, the registered number of stillbirths, the registered numbers of live births and of DS stillbirths affected with DS, amniocentesis rates each year in pregnant women aged 35 or more, and the age distribution of pregnant women in Taiwan. The live birth rate of and total birth rate of fetuses affected with DS, and the rates of live birth and stillbirth to total birth with DS, were analyzed year by year, in order to understand the change of birth rate of infants affected with DS between 1993 and 2001. Those with isolated cleft palate (ICP) were also analyzed as internal control variable. Confidence interval of live birth rate of infants with DS under Poisson distribution was calculated. Chi-square test for trend in binomial proportions was performed to see if there is an increasing (or decreasing) trend in the proportion of incidence of fetuses affected with DS. The difference was statistically significant if a p value was <0.05.
A total of 1 331 616 deliveries were collected during the study period, including 840 cases of DS confirmed by karyotyping study. A marked decrease in the live birth rates of case with DS occurred in 1994-95, from 0.63 per 1000 births to 0.23 per 1000 births. There was a crossover from more live births with DS to more stillbirths with DS during 1994 to 1996 after the implementation of second-trimester maternal serum screening for DS in 1994. In 1993, 76.9% of births diagnosed with DS were born alive, compared to 32.5% in 2001 (p < 0.001).
The policy of prenatal diagnosis program including amniocentesis for pregnant women aged 35 or more and the liberal application of maternal serum screening for DS in younger women was responsible for the marked decrease in the live births affected with DS in Taiwan from 1993 to 2001.
本研究旨在确定1994年起在台湾广泛应用的孕中期母血清筛查是否对过去十年中唐氏综合征（DS）患儿的出生患病率产生了可衡量的影响。
我们的研究基于台湾的“全国出生缺陷登记与通报系统”、“孕妇羊膜穿刺术”和“人口统计年鉴”数据库。收集的数据包括总登记出生数、死产登记数、活产登记数以及患DS的死产登记数、每年35岁及以上孕妇的羊膜穿刺术率，以及台湾孕妇的年龄分布。逐年分析患DS胎儿的活产率和总出生率，以及患DS的活产和死产占总出生的比率，以了解1993年至2001年期间患DS婴儿出生率的变化。孤立性腭裂（ICP）患者也作为内部对照变量进行分析。计算泊松分布下DS患儿活产率的置信区间。进行二项式比例趋势的卡方检验，以查看患DS胎儿的发病率比例是否有上升（或下降）趋势。如果p值<0.05，则差异具有统计学意义。
研究期间共收集了1331616例分娩数据，其中840例经核型分析确诊为DS。1994 - 1995年，DS患儿的活产率显著下降，从每1000例出生0.63例降至每1000例出生0.23例。1994年实施孕中期DS母血清筛查后，1994年至1996年期间出现了从患DS活产儿较多到患DS死产儿较多的转变。1993年，诊断为DS的婴儿中76.9%为活产，而2001年这一比例为32.5%（p < 0.001）。
包括对35岁及以上孕妇进行羊膜穿刺术的产前诊断计划政策以及对年轻女性广泛应用DS母血清筛查，是导致1993年至2001年台湾患DS活产儿显著减少的原因。
