PRENATAL-DIAGNOSIS BY TRANSABDOMINAL CHORIONIC VILLUS SAMPLING IN THE2ND-TRIMESTER AND 3RD-TRIMESTER

From October 1989 through December 1993, 124 pregnant women (114 in th e second trimester and 10 in the third trimester) underwent transabdom inal chorionic villus sampling (CVS) for prenatal molecular or cytogen etic diagnosis. The mean gestational age was 18.2 weeks. Indications f or CVS comprised single gene disease (72%), fetal anomalies detected b y ultrasound (17%), advanced maternal age (6%), and previous siblings with chromosomal aberration (5%). Among the 89 fetuses at risk for sin gle gene disease, 20 were diagnosed as affected by DNA analysis. Among the 35 fetuses at risk for chromosomal anomaly, 4 had trisomy, 3 had a 45,XO karyotype and 2 had a structural chromosomal abnormality. The miscarriage rate was 1.8% (2/114) and the spontaneous preterm birth ra te was 2.4% (3/124). No maternal or other fetal complications occurred . This study suggested that second- and third trimester CVS is a safe and useful method for prenatal diagnosis.