Clinical Analysis of 501 Cases of Mid-trimester Genetic Amniocentesis

Park, Seon Young; Moon, Jeong Beom; Kim, Hyun Seong; Kim, Kyoung A; Kim, Young Sook; Lee, Keum Nho

Abstract

OBJECTIVE
To analyze the change of indications and chromosomal abnormalities according to pateint's age and indications in midtrimester genetic amniocentesis.
METHODS
This study reviewed 501 prenatal genetic amniocentesis cases from June 1995 to April 2004 which were done at Presbyterian Medical Center. We analized the changes of the indication, age distribution and chromosomal results according to maternal age and indications of amniocentesis.
RESULTS
In 501 cases, the most common maternal and gestational age distributions were 30-34 years old and 17 weeks (32.54% and 25.98%, respectively). Abnormal maternal serum markers were the most common indications for amniocentesis (46.9%), and followed by old age (24.96%), combined old age and abnormal maternal serum screening (14.38%), ultrasonographic abnormality (4.60%). The overall incidence of chromosomal abnormalities were 3.79% (19 cases), of which numerical abnormalities and structural abnormalities were 1.79% (9 cases) and 2.0% (10 cases), respectively. In autosomal disorders, Down syndrome 4 cases, translocation 3 cases, mosaicism 2 cases, deletion 1case were diagnosed. In sex chromosomal disorders, Turner syndrome 1 case and mosaicism 2 cases (Turner syndrome 1 case, Triple X chromosome 1 case) were diagnosed. No statistic significance was found among different age groups. Those who had ultrasonographic abnormalities were found to have correlation with chromosomal abnormalities than other indications.
CONCLUSION
Among the several indications for prenatal cytogenetic diagnosis, ultrasonographic abnormalities and abnormal maternal serum markers might be important indications. Especially, ultrasonographic abnormalities could be the most predictive markers for abnormal fetal karyotypes.