Committee Opinion No.682: Microarrays and Next-Generation Sequencing Technology: The Use of Advanced Genetic Diagnostic Tools in Obstetrics and Gynecology.

Genetic technology has advanced dramatically in the past few decades, and its applications and use in caring for and counseling pregnant women has been transformational in the realm of prenatal diagnosis. Two of the newer genetic technologies in the prenatal setting are chromosomal microarray and whole-exome sequencing. Chromosomal microarray analysis is a method of measuring gains and losses of DNA throughout the human genome. It can identify chromosomal aneuploidy and other large changes in the structure of chromosomes as well as submicroscopic abnormalities that are too small to be detected by traditional modalities. Prenatal chromosomal microarray analysis is recommended for a patient with a fetus with one or more major structural abnormalities identified on ultrasonographic examination and who is undergoing invasive prenatal diagnosis. Whole-genome sequencing analyzes the entire genome, including noncoding regions (introns) and coding regions (exons). However, because the introns are typically of little clinical relevance, there has been a focus instead on whole-exome sequencing, which examines the coding regions (exons) of the genome. The exons generally have greater clinical relevance and applicability to patient care. However, the routine use of whole-genome or whole-exome sequencing for prenatal diagnosis is not recommended outside of the context of clinical trials.