Results
Among stillbirth fetuses included in this study (n=387), there were 60 (15.6%) with abnormal CNVs (40 [10.3%] with pathogenic, and 20 [5.2%] with VOUS CNVs) and 327 (84.5%) with normal CNVs. Comparisons of proportions showed that stillborn fetuses with abnormal CNVs tended to be born to older women, of Hispanic ethnicity, and anomalous in comparison to those with normal CNVs (Table 1 ). Stillborn fetuses with abnormal CNVs did not differ from those with normal CNVs in regard to other socio-economic factors, parity, fetal sex, maternal chronic hypertension, preeclampsia, diabetes and gestational diabetes.
The proportion of stillborn fetuses with maternal vascular pathological lesions was higher among those with abnormal CNVs in comparison to those with normal CNVs (81.7% vs. 64.2%; p=0.008; Figure 1 ;Table S2 ). However, the proportions of stillborn fetuses with fetal or any (i.e. fetal or maternal) vascular pathological lesions among those with abnormal CNVs were similar in comparison to those with normal CNVs (78.3% vs. 77.1%; p=0.8, 95.0% vs. 90.8%; p=0.3, respectively). Furthermore, the proportions of stillborn fetuses with maternal inflammatory, fetal inflammatory, any inflammatory or immune/idiopathic placental pathological lesions among those with abnormal CNVs were similar in comparison to those with normal CNVs (25.0% vs. 33.3%; p=0.2, 11.7% vs. 15.6%; p=0.4, 28.3% vs. 36.2%; p=0.2, and 15.8% vs. 10.4; p=0.3, respectively). Pathogenic deletion CNVs (n=4) in three stillborn fetuses and pathogenic duplication CNVs (n=4) in five stillborn fetuses with maternal vascular pathological lesions were identified (Table 2 ). Two stillborn fetuses with maternal vascular pathological lesions also had VOUS deletions CNVs (n=3), and thirteen stillborn fetuses with maternal vascular pathological lesions had VOUS duplications CNVs (n=14) (Table S3 ). Three stillborn fetuses with maternal vascular pathological lesions had multiple abnormal CNVs. Specifically, CNV 22q11.21 deletion, 16p13.11 duplication, and 4q32.3q35.2 and 17p13.3 were identified in stillborn fetuses with maternal vascular pathological lesions. The deletions and duplications each involved several genes, including theMYH11 (myosin heavy chain 11) and HNF1B (hepatocyte nuclear factor 1B) genes.