Interest of chromosomal microarray analysis in the prenatal diagnosis of fetal intrauterine growth restriction

The aim of this study is to evaluate the diagnostic utility of prenatal diagnosis using the chromosomal microarray analysis (CMA) for fetuses presenting with isolated or associated intrauterine growth restriction (IUGR).

We retrospectively included all fetuses with IUGR referred for prenatal testing and studied by rapid fluorescence in situ hybridization (FISH), karyotype, and CMA.

Among the 162 IUGR fetuses (78 associated and 84 isolated IUGR) included, 15 had an abnormal FISH result: 10 associated and five isolated fetal IUGRs. Among the 143 fetuses studied by CMA, 10 (7%) presented pathogenic copy number variations (CNVs). All 10 were in the associated fetal IUGR group (10/65 or 15.4%; 95% confidence interval [CI]: 8.4%-26.2%) versus 0/78 in the isolated fetal IUGR group (95% CI: 0%-5.6%). Six fetuses (4.2%) carried variants of unknown significance (VOUS) (three associated and three isolated fetal IUGRs).

Our study highlights the added value of CMA in the case of associated fetal IUGR with an incremental yield of 6.1% (4/65) over karyotyping. No pathogenic CNVs were reported in the isolated fetal IUGR group. More studies must be conducted to determine when and whether CMA would be wisely indicated in this population.