Prenatal cytogenetic diagnosis in Taiwan

Purpose: The goal of this study was to gain a better understanding of the status of advanced maternal age among criteria for provision of amniocentesis in pregnant women in Taiwan. Materials and method: Data of 315 670 second-trimester amniocenteses from 28 national certified cytogenetics laboratories were retrospectively analyzed from the Prenatal Genetic Diagnosis Declaring and Database System of the Health Promotion Administration, Ministry of Health and Welfare in Taiwan between 2006 and 2013. Results: The number of pregnant women undergoing amniocentesis in Taiwan between 2006 and 2013 increased, and the most common three indications for amniocentesis were advance maternal age (75.11%), abnormal second trimester maternal serum screening (13.22%) and abnormal sonographic finding (8.00%). Down syndrome was the most common autosomal abnormality identified (25.74%); Turner syndrome was the most common sex chromosome abnormality (7.04%). Of structural rearrangements, 26.93% were balanced translocations and 17.10% were unbalanced translocations. The greatest proportion of fetal chromosomal abnormalities was found in cases where parents were also affected (38.02%). Conclusions: Clinical workers should provide detailed genetic diagnostic information to pregnant women, especially those with the common amniocentesis indications, which will enable them to determine a birth plan.