The evolving national birth prevalence of Down syndrome in Taiwan. A study on the impact of second-trimester maternal serum screening

• Published in: Prenatal diagnosis 2005-08, Vol.25 (8), p.665-670
• Main Authors: Jou, Hei-Jen, Kuo, Yih-Shing, Hsu, Jenn-Jeih, Shyu, Ming-Kwang, Hsieh, T'sang-T'ang, Hsieh, Fon-Jou
• Format: Article
• Language: English
• Subjects: Age Distribution; Amniocentesis - statistics & numerical data; Biological and medical sciences; Birth Weight; Chi-Square Distribution; Chromosome aberrations; Confidence Intervals; Down syndrome; Down Syndrome - blood; Down Syndrome - epidemiology; Down Syndrome - prevention & control; Female; Gynecology. Andrology. Obstetrics; Humans; Karyotyping; Live Birth - epidemiology; live births; Management. Prenatal diagnosis; Mass Screening - methods; Mass Screening - statistics & numerical data; Maternal Age; maternal serum screening; Medical genetics; Medical sciences; Poisson Distribution; Pregnancy; Pregnancy Trimester, Second; Pregnancy. Fetus. Placenta; Prenatal Diagnosis - methods; Prenatal Diagnosis - statistics & numerical data; Prevalence; Registries; second trimester; Stillbirth - epidemiology; Taiwan - epidemiology
• ISSN: 0197-3851; 1097-0223
• DOI: 10.1002/pd.1220

Objectives 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. Methods 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