Copy number variation characterization and possible candidate genes in miscarriage and stillbirth by next-generation sequencing analysis

Background The present study aimed to explore the etiological relationship between miscarriage and stillbirth and copy number variations (CNVs), as well as provide useful genetic guidance for high-risk pregnancy. Methods In total, 659 fetal samples were recruited and subjected to DNA extraction and CNV sequencing (CNV-seq), relevant medical records were collected. Results There were 322 cases (48.86%) with chromosomal abnormalities, including 230 with numerical abnormalities and 92 with structural abnormalities. Chromosomal monosomy variations mainly occurred on sex chromosomes and trisomy variations mainly occurred on chromosomes 16, 22, 21, 18, 13 and 15. In total, 41 pathogenic CNVs (23 microdeletions and 18 microduplications) were detected in 27 fetal tissues. The rates of numerical chromosomal abnormalities were 29.30% (109/372), 32.39% (57/176) and 57.66% (64/111) in < 30-year-old, 30-34-year-old and >= 35-year-old age pregnant women, respectively, and increased with an increasing age (p < 0.001). There was statistically significant difference (chi(2) = 7.595, p = 0.022) in the rates of structural chromosomal abnormalities in these groups (13.71%, 18.75% and 7.21%, respectively). The rates of numerical chromosomal abnormalities were 45.44% (219/482), 7.80% (11/141) and 0% (0/36) in the <= 13 gestational weeks, 14-27 weeks and >= 28 weeks groups, respectively, and decreased with respect to the increasing gestational age of the fetuses (p < 0.001). Conclusions The present study has obtained useful and accurate genetic etiology information that will provide useful genetic guidance for high-risk pregnancies.