ABSTRACT
The first reported attempts to utilize fetal and/or placental tissue for prenatal genetic diagnosis occurred in 1 955 , when Serr et al. ( 1 ) and Fuchs and Riis (2) reported the ability to determine fetal sex through sex chromatin studies on amniotic fluid cells . Eleven years later, Steele and Breg (3) reported the successful culture of amniotic fluid cells and its use to examine fetal chro mosome status . The next year Jacobson and Barter (4) applied the technique to diagnose a DID translocation in a fetus . In 1 968, both Valenti et al . (5) and Nadler (6) reported the diagnosis of a fetus with Down syndrome in utero. In the same year, Nadler (6) reported the in-utero diagnosis of a fetus affected with galactosemia. Chorionic villus sampling (CVS) was first re ported in the late 1 960s (7). However, technical difficulties with sampling relegated the technique to obscurity until ultrasound improvements allowed for direct monitoring of the procedure. Additional improvements, such as the development of a flexible catheter for transcervical sampling and a protocol for transabdominal sampling, markedly improved the success rate of CVS sampling and the safety of the procedure. Fetal blood sam pling and biopsy of other fetal tissue began with fetoscopy (8) but have proven to be more successful and safer when performed under ultrasound guidance.
