Whole Exome Sequencing in a Population of Fetuses With Structural Anomalies.

Objective: To investigate the exome sequencing (ES) detection rate among fetuses with congenital anomalies and describe the rates in the setting of multiple versus isolated anomalies, perinatal autopsy, and family history of a previously affected child.

Methods: A single-center retrospective chart review was conducted on 397 anomalous fetuses that underwent ES from May 2012 through December 2023. Medical record review included demographics, imaging, and genetic testing.

Results: The overall ES diagnostic rate was 34.3%. The rate of diagnosis was 31.6% in fetuses with a single anomaly and 42.6% in fetuses with 4 or more major organ systems involved. Of the fetuses with a single anomaly, lymphatic, craniofacial, skeletal, and neurological anomalies had the highest diagnostic rate on ES. 38.6% of deceased fetuses who underwent autopsy had a genetic diagnosis. Additionally, families who had a previously affected child had a 45.5% diagnostic rate.

Conclusions: ES is an important tool that should be offered in pregnancies affected with congenital abnormalities or at the time of fetal demise or termination. The diagnostic rate of ES in the prenatal setting is also highly dependent on comprehensive phenotyping. With diagnostic ES results, reproductive technology and testing options are available in subsequent pregnancies.