EARLY TRANSABDOMINAL CHORIONIC VILLUS SAMPLING IN COUPLES AT HIGH GENETIC RISK

OBJECTIVE: The purpose of the study was to evaluate the feasibility and safety of transabdominal chorionic villus sampling before 9 weeks' gestation. STUDY DESIGN: Two hundred pregnancies at risk for beta-thalassemia (n = 198) or Duchenne muscular dystrophy (n = 2) underwent transabdominal CVS at 6 through 8 weeks. Sampling success and fetal loss are expressed in percentages. RESULTS: Sampling was successful in all cases (100%). Forty-eight fetuses were affected by beta-thalassemia and one by Duchenne muscular dystrophy. The percentage of fetal loss, expressed as a proportion of continuing pregnancies, was 4.0%. All women (n = 144) have been delivered, and no misdiagnoses have occurred. We observed one anencephalus and one mild limb defect consisting of absence of distal phalanges of index and little fingers of both hands and distal phalanges of both little toes. CONCLUSION: Transabdominal CVS before 9 weeks is a reliable and relatively safe method for prenatal diagnosis in patients at high risk for genetic diseases. However, further studies are necessary to assess the risk to the fetus.