This study aims to systematically evaluate the diagnostic yields of karyotyping, chromosomal microarray analysis (CMA), and whole-exome sequencing (WES) in an unselected cohort of fetuses with fetal growth restriction (FGR). A total of 129 FGR fetuses were included, of which 64 underwent all three genetic tests, enabling a head-to-head comparison. Among these 64 cases, WES detected genetic variants in 25.0% (16/64), compared to 9.4% (6/64) for CMA and 3.1% (2/64) for karyotyping. Notably, in cases negative by both karyotyping and CMA, WES provided an additional diagnostic yield of 15.6%. Even in isolated FGR, WES identified variants in 23.6% (13/55) of cases. Follow-up data at one year of age revealed that infants born after FGR had an increased risk of postnatal growth retardation (16.1%) and delayed language development (9.7%). This study demonstrates that in a real-world, phenotypically unselected FGR cohort, WES substantially increases variant detection, particularly in cases where conventional testing is negative.
Liu et al. (Tue,) studied this question.