Subjects.
we collected 14 products of conception in the present study, from the First Affiliated Hospital of Zhengzhou University (Zhengzhou China),who were normal for karyotype and chromosome microarray analysis between October 2020 and February 2021.Among the 14 cases, 7 fetuses were diagnosed as congenital developmental abnormalities by ultrasound, and the parents chose to terminate the pregnancy. The remaining 7 fetuses were intrauterine stillbirths of unknown causes. The time of fetal death or termination of pregnancy occurs between 8 and 26 weeks, and the average gestational age is about 18 weeks. Six cases were less than 12 weeks old. All the couples were not first Cousins. Through inquiring the medical history and inquiring the relevant clinical examination results, it can be found that none of the 14 cases had a clear family history of genetic diseases. The pregnant women themselves have no uterine abnormalities, hypertension, diabetes and other basic diseases, the age of 25-34 years old. The villus tissue, fetal skin tissue and the peripheral blood of the husband and wife were extracted from the fluid products and tested by Trio-WES. The present study was approved by the ethical committee of the First Affiliated Hospital of Zhengzhou University. Written informed consent was obtained from each participant.