Midtrimester Amniocentesis for Antenatal Diagnosis of Genetic Disorder : Chulalongkorn Hospital Experience

Abstract

Results of amniocentesis for prenatal diagnosis at Chulalongkorn Hospital have been studied during June 1991 to May 1992. A total of 250 pregnant women with 261 amniocentesis fluid samples were included in this study. Most of the indications are maternal age older than 35 years. The incidence of chromo somal abnormality detection in the mother older than 35 years of age is 13.57/1000 amniocenteses, while no chromosomal abnormality detected in mother less than 35 years of age. We further analyse the two methods used for amniocentesis, one with ultrasound guidance and the other with ultrasound located at the site of puncture. The two methods did not differ in blood contamination in amniotic fluid nor the number of punctures. Also there was no abortion related to both procedures. The cost analysis for performing amniocentesis in the mother age beyond 35 is very reasonable according to our study. In conclusion, amniocentesis is a safe method for prenatal chromosome diagnosis and recommended for mothers who are older than 35 years old. (Thai J Obstet Gynaecol 1994;6:43-49.)