Great strides have been achieved in the antenatal diagnosis of chromosomal disorders. At present, antenatal chromosomal diagnosis is definitely appropriate in the following circumstances: maternal age over 35 years, previous infant or parent with aneuploidy, presence of a translocation or inversion in a parent, increased risk for an X-linked recessive disorder, and risk for certain chromosomal breakage syndromes. Other potential indications have been considered, but none is sufficiently established to justify routine clinical application. Future investigations should establish the significance of these alternative potential indications. However, the optimal approach would involve noninvasive techniques that could be applicable in all pregnant women.
