ABSTRACT
The increased availability of prenatal diagnosis has stimulated the development of screening for genetic disease. Clinically significant chromosomal defects occurred in 0.65% of all births before prenatal diagnosis was introduced; an additional 0.2% of infants were born with balanced structural chromosome rearrangements. Couples appreciate the opportunity for a counseling session and discussion, and the offer of prenatal diagnosis will be accepted by most of them. The nature of the disorder/problem itself, and the impossibility/possibility of prenatal diagnosis, will affect the way it is perceived. The couples decide whether or not to undertake pregnancy and they decide whether or not to accept an offer of prenatal diagnosis. In some autosomal or X-linked recessive situations, prenatal diagnosis is, at present, impossible, even though the genetic risk is high. In late first and early second trimesters, prenatal diagnosis of fetal anatomy by ultrasound became a major factor leading to termination.
